http://www.sofurry.com/view/11016/guest

If you liked this story, also check out:
https://legendsofbelial.net/viewtopic.php?id=4382
https://legendsofbelial.net/viewtopic.php?id=4313

---

A Horse of Another...
by Theo Winters

Written for Mozdoc

Mozdoc let out a groan as the lights switched on above him, the light filtering through the black clothing that had been tied over his eyes. He grunted through his gag and pulled at the bonds on his wrist, trying to call out to whoever was in the room.

"Oh god, Mozdoc!" he heard Shelly call out, followed by the sounds of footsteps rushing over to him. Moments later hands were on him and the blindfold was pulled free. He blinked in the bright light, his eyes finally focusing on Shelly's narrow face and blue eyes.

"What happened? Are you alright?" she asked as James pulled the gag from his mouth.

Mozdoc gasped and smacked his lips, trying to return some of the moisture that the gag hand drawn from the skin. "Some nuts broke into the lab, let the horses loose," he said, coughing a bit.

"We got the horses all rounded up, no harm to them," James said as he cut the other man's bonds. Mozdoc was glad to get his wrists free and rubbed them with his fingers, trying to get the circulation back.

Shelly slowly helped him out of the chair as she looked around the lab, taking in the damage. "It looks like they dumped all the serum. This will set us back six months."

He coughed as he came to his unsteady legs. "They didn't dump it, they made me drink it," he said.

James and Shelly looked at him, the darker skinned man's face pulling into a deep frown. "There was four and a half gallons!"

Mozdoc belched and rubbed at his stomach, which still felt bloated from having drunk so much. His back end was starting to feel the pressure as well. "Every drop, James, every god damn drop," he said and grimaced. "I've got to piss like a horse," he said.

"No surprise there. Let's get a urine sample as well, we need to know how it affects the human system," James said as he helped the other man walk across the damaged lab.

"I doubt it will be much use with this large of an overdose," Mozdoc replied, walking with a bit of a waddle, swinging his legs wide. His inner thighs were aching and letting them rub together hurt too much.

James nodded his head and continued with the younger man until they reached the restroom. He handed Mozdoc a sample cup then patted him on the back. "We'll be in the infirmary when you're done," he said.

Mozdoc nodded and stepped into the bathroom. "Don't expect me to be fast about it," he said as he closed the door.

Turning in the bathroom, he looked at himself in the mirror. He had dark bags around his eyes, and he desperately needed a shave; his beard was dark against his light skin. He splashed some water on his face and rubbed at his eyes, his fingers tingling still from the bindings.

He brushed his dark hair back and turned to the toilet, working his pants free and pulling his dick out. He held it in one hand and the specimen cup in the other. With a sigh he let the stream out, catching it in the cup until it was full. He closed the cup, set it aside, and let lose into the water of the toilet.

As the urine streamed out he started to relax, trying to forget the hours of drinking the thick serum. Glass after glass, gallon after gallon, all pouring into him. After a while he felt like he was pushing out just as much as was put into him.

After what felt like an hour the stream finally came to an end, the last few drops falling from his limp cock. It felt different in his hand, thicker than he normally was. It probably was just irritation from having to push out so much water from his body.

He zipped up and washed his hands, then headed to the infirmary. He walked into the narrow room and handed the sample cup to James. "Here, do what you want with it," he said.

"Thanks," the other man said, setting the sample to the side. "Shelly and I have been talking, if we shut down the processing for the bovine hormones we should double our output. We'll still be behind, but only by half the time."

Mozdoc waved his hand and sat down on the examination table. "That could work, I think we could also speed up the processing if we tighten up the hormone threshold," he said, wincing as Shelly started to draw blood.

"It's not being behind that gets my goat," she said as she pulled out her sample. "It's that were trying to help animals here, trying to get horses to breed again before they are extinct, and they had to come here and fuck it all up." The swearing did not come naturally to her, and it sounded odd.

With a shrug of his shoulders Mozdoc pressed a cotton ball to where the blood was drawn from, his stomach starting to growl. "I just want to walk around and get something to eat. We'll bring the stills back up tonight. Right now I'm starving," he said.

"Moz, it's six in the morning, we need to file a police report, call the institute and--" Shelly started to say.

He cut her off with a wave of his hand, his stomach twisting into a knot. "I feel like I haven't had anything to eat in a week. We can talk about things while I eat, but I need to get something into me, now," he said.

"Fine, we'll get something to eat," James said and walked out of the room. The others followed after him, Mozdoc continued to waddle, his legs feeling swollen as he moved. His fingers still tingled, and his hands felt stiff. His feet had also started to feel odd, pinching in his shoes.

He started to say something, but the smell of the food in the kitchen hit him, and eating became the only thought in his mind. He skipped right past his usual bacon and eggs, and instead went for the oatmeal, heaping three bowls full before setting them down on the table and starting to shovel the food into his mouth.

The other two watched in surprise as their fellow scientist shoved heaping spoonfuls of the sticky food past his lips. His eyes narrowed as he emptied the first bowl in only a couple of minutes, and started on the second one.

"Are you feeling okay?" Shelly asked.

Mozdoc nodded and waved his free hand at her. Under the table he slipped his shoes off to relive the pinching on his toes.

"This must be a side effect of the overdose," James said.

She nodded in agreement as she turned to look at the other man. "It has to be, but I've never seen anything like it before. None of the horses we tested reacted like this."

He shrugged and started to make notes. "None of the horses got a ten-thousand times dose," he said.

Mozdoc continued to ignore them as he finished the second bowl. He pushed it aside as he started on the third, his fingertips starting to darken around the nails. A few moment later he let out a suppressed howl as he felt his toes shift and compress in ways they weren't meant to.

"What's wrong?" James asked as he rushed around the table, Shelly only a moment behind. The feeling had snapped Mozdoc back into the real world and he pulled his legs up from under the table to show his colleagues. His socks were deformed and something was pressing against the ends of them.

James moved fast, pulling the socks off his friend's feet, and letting out a gasp at what he saw. The toes had nearly vanished, the outer digits having pulled back against the foot while the two inner ones had become swollen and dark and were growing thicker while they watched. In a minute the toes had vanished completely, being replaced by a set of large horse hooves.

"Oh shit!," Mozdoc said, looking down his new limbs.

"Back into the infirmary, now!" James snapped. He and Shelly lifted their injured friend to his feet and helped him walk. Each step echoed with the clop of his hooves.

Mozdoc grunted softly. Each stride pinched at his legs. A prickling feeling vas starting to spread around his body, tickling under his clothing. By the time he reached the infirmary it was everywhere.

"His hands are changing as well," Shelly observed.

He looked down at his hands and grimaced when he saw that the tips of each of his fingers and thumb had turned black. The surfaces were rough and hard, hooves in their own right.

James pulled a light out of the table and checked at Mozdoc's eyes, frowning at what he saw. "Your reactions are all wrong," he said, then his frown deepened as he looked at the hair on his friends face.

"Strip, now," the older man ordered.

"Why?" Mozdoc asked, his head feeling clouded by all that was going on.

"You're growing fur," James said.

Mozdoc paused for a second, then nodded and started to pull his clothing off. His shirt was easy, it came off without any trouble, but he fumbled at the button of his pants. James reached in to help, working the pants open and pulling them off his friend's legs. He let Mozdoc keep his briefs on, allowing him to keep some modesty.

The changing man looked down over his body. Brown fur covered his arms and legs and was starting to spread up his body and over his lower face. His let out a soft gasp when he realized that the bulge in his briefs was significantly larger than he remembered.

"I need a second blood sample from him, and get a camera, I want to at least document this!" James said as he started to pull out medical equipment.

Mozdoc grunted and glared at the older man. "I'm not a specimen or an experiment! No pictures!" he snapped, his tongue feeling thick in his mouth. He still felt twisted up inside, but it wasn't his stomach or anything connected to it. Something else was going on inside of him.

"I'm sorry, Mozdoc. We should document this, but I can understand. No pictures," he agreed. Beside him Shelly started to draw a second blood sample. His skin was starting to vanish under a thick coat of horse hair.

"Something else is going on," Mozdoc said, then jumped from the table, reaching back to grab at the top of his ass. A bulge had grown under the white cotton of his briefs. He yanked the material down under the nub, and watched as hair pushed from the skin of what seemed to be an extension of his spine. The long heavy hair almost seemed to explode outwards, falling towards the floor, leaving him with a long horse tail.

James reached out to touch the tail, then took a grasp of a single hair and pulled it free.

Mozdoc jumped and let out a snort, his nose flattening out as he glared at the other man. "That hurt!" he bellowed.

"Sorry, I just want to be sure this is horse hair," James replied, taking a few steps from the angry looking horse man.

Shelly sighed and walked past the older man. "You can tell that just by looking at him. The rest of his hair has become horse hair as well, and his ears," she said.

Mozdoc reached up and touched his head, feeling that his ears had grown longer, into mobile points that twisted about his fingers. His hair reached down his back by then, brushing at the top of his new tail. His legs felt thick, heavy and ungainly, his briefs full and pulled tight against his skin.

He tried to say something, but his tongue didn't work. His teeth started to ache, pushing against each other as they seemed to grow thicker. Then with a groan his face started to push out, his lips stretching as a muzzle grew until he had the head and face of a large horse.

Still his insides felt strange, pushing back at the space between his scrotum and his anus. It felt tight and stretched in a way that it shouldn't be as things shifted around.

Shelly walked up to him, her hands stroking on the fur of his neck, except it wasn't her hands that were moving, but his neck was growing longer.

"Is he going to become a horse?" she asked with a touch of fear.

"I hope not," Mozdoc said, his voice muffled by his long muzzle and thick lips.

James shook his head as he looked over his transformed friend. "I don't think so, most of the changes seemed to have stopped," he said.

"Not all of them," Mozdoc said as he adjusted himself on his hooves. His legs felt like tree trunks, thick and hard to move. He looked down at his body, noting that he had lost any extra fat he may have had, the fur outlining a tight set of well defined muscles, and his belly button had vanished. The front of his briefs were straining, bulging hugely forward, the fabric creaking as he kept growing.

With a snap and a ripping sound his overtaxed briefs almost exploded outwards. A huge horse cock flopped forward, trailing down nearly to his knees. Behind that was a tremendous set of testicles, each one the size of a mans fist and still growing.

The group of them were all familiar with the equipment of stallions, but they all stared at this. Finally Mozdoc turned away, trying to cover himself as he felt his hips and pelvis shift. His legs pulled apart far enough to give his new equipment room as the last shred of clothing fell away.

"Something's happening to your legs," James said as he watched the skin start to ripple around the lower limbs and crease down their length.

Mozdoc craned his head down and looked at his legs, letting out a groan as they split in two, leaving him with four horse legs. They stayed connected at the hooves for a moment before they separated completely. He shuffled his new feet, trying to strike a balance with them and finding it easy to be a quadruped. Even as he stood he could feel his hind legs starting to slide back over the floor as his spine lengthened and the flesh between his legs started to fill out.

"You're becoming a centaur," Shelly said as she watched her friend change. His new lower body had growing thicker, his legs spreading out ever wider until there was now no doubt that his new form was equine. His sheath formed around his huge equipment, holding it to his belly as his balls continued to swell behind his hind legs.

Finally the changes seemed to come to a stop, his transformation complete except for the swelling between his legs.

Mozdoc panted, his hands wrapped around the edge of the table as he shuffled his four legs. "This is beyond reason! How could this have happened?" he asked the others.

James shook his head as he walked around his friend, finding now that he had to took up into the large horse eyes. "I don't know; the serum was meant to tweak the DNA, but never on this scale," he said, then frowned when he noticed something on his friend's chest. Even changed he still had nipples, but they had become huge, jutting out from his chest and slowly rising as flesh began to fill out around them.

"I'm growing breasts!?" the centaur said in surprise and anger. "Why am I growing breasts?!" he demanded as he pawed at his chest, feeling the soft flesh grow outwards into a sizable pair of breasts.

Shelly provided his answer when she grasped his tail and lifted it high. "Because not only are you a stallion, you're a mare," she said as she let the tail go.

"Total cross gender hormonal replacement," James said in awe. "This is going to make us famous!"

Mozdoc swung his head around and glared at the scientist. "I don't want to be famous! I want to be _human_, not some four-legged hermaphrodite freak," he said, slamming his hoof to the floor.

"Can we change him back? We don't even know how this happened," Shelly asked, a frown crossing her narrow features as she thought about the possibilities.

James rubbed his chin as he walked past Mozdoc's horse body. "It might be... It's really not your natural form, so if we can halt the hormones we might be able to reverse it," he said.

"That could take months," Mozdoc protested.

The man shrugged and continued to circle around his friend. "Yes it could, but any cure will take time. I think I can come up with something before the serum is due,"

Shelly's frowned deepened. "Due? We can't let the serum out if it can do this!" she snapped.

"Nonsense, it only did this because I took in gallons on the stuff, and not by choice. This isn't a risk," the centaur said his arms crossed over his chest.

She sighed and nodded her head. "I suppose, but I'm doubtful about it. We should write a paper about the side effects of this kind of mega-dose," she said. Mozdoc started to protest but she cut him off. "We won't tell anyone what happened to you, but we should at least raise the possibility of it. That way we wouldn't look so bad if it happens again."

James thought about it for a few moments then nodded his head. "Only if Mozdoc approves," he finally said.

"Oh I approve!" the centaur replied with another smack of his hooves.

The older man nodded his head and let out a long sigh. "We still need to produce the serum if we have any hope of being able to publish anything. Mozdoc, do you think you can still do your job?"

He looked down at his thick fingers, flexing then gently. Even with the stiff finger tips he was sure he could still use the equipment. "I think I can, I'll work on converting the second still for the horse serum. It will take a bit longer but I'll have it done by tonight. What time is it anyway?" he asked.

"Eleven in the morning," Shelly answered.

He nodded as his stomach rumbled, shaking his lower body as the growling lasted for almost a minute. "You better bring me some food, I'm still starving," he said with a frown and walked out of the room. His large scrotum swayed from side to side behind his hind legs, the testicles still growing inside the taunt skin.

* * *

True to his word Mozdoc worked past sunset and into the night. It was taxing at times, his new body just didn't work the way he expected it to, and it made adjusting anything hard work. His extra bulk didn't help either, for most of the day his large hind quarters knocked over almost everything in the lab. Luckily nothing had been broken.

He had finally moved everything to be close at hand, and he had been able to stand in one place as he proceeded with his work. His body still demanded food, his stomach growling with no end in sight. His coworkers had provided a steady supply of food, but none of it had done anything to slack the hunger.

Carefully he adjusted the equipment of the still, so it would produce the correct serum. It was careful work, tedious and exacting, but he was nearly finished with his task.

He shifted his hind legs slightly, adjusting himself to try and relieve the low aching of his huge scrotum. It had continued to swell as the day went on, bulging out around his hind legs and back under his colossal sheath. That had grown as well, and was now resting under three fourths of his equine body.

Mozdoc tried to ignore it, but it was growing more difficult as the pressure increased under him. He grunted softly as he shifted his legs again and shoved in another mouthful of food. After gathering himself for a moment he added the last few chemicals and leaned back in satisfaction, his changes to the still done.

He wiped his hands clean and finished the last of his food before he turned around, and was surprised to find Shelly standing at the laboratory door.

"How are you doing?" she asked with a slight blush as she looked down at the mass behind his hind legs.

"I'm still hungry," he grunted as he walked towards her, swinging his hind legs wide to move around his pendulous balls.

She shook her head and took a few steps closer to him. "I understand; I'll try to get you more food," she said as he maneuvered his way out the door.

Mozdoc walked down the hallway, heading towards his room, the woman following behind him. "Your equine half looks healthy, even if your rump is a bit large," she observed as they walked.

He flicked his tail at her, but said nothing until he came to his room. He looked inside the door then frowned and slammed his hoof against the floor. "It's too damn small! I'll never fit inside that," he said.

"You could always sleep in one of the stalls," she suggested.

His frown deepened as he considered the possibility. He didn't like the idea of sleeping in the barn like an animal, but there didn't seem to be another choice. He struggled into his room and picked up a pillow and a blanket, then walked back into the hallway.

"Let me give you a hand," Shelly offered as she reached for his things.

"I'd rather you didn't," he replied as he walked down the hallway. "Being watched at all times is not enjoyable. I just want to be alone," he said.

She nodded a bit and backed away from him. "I'll leave you in peace then," she said, pausing for a moment like she was hoping for him to say something. When no words came she turned from him and walked away.

Mozdoc let out a long sigh and started down the hallway. He didn't like pushing his friends away, but it was clear to him that they saw him as some kind of freak. He just wanted them to treat him as himself, and to find a way to turn him back to normal.

He pushed the door open and stepped out of the labs. He could see the barn a few hundred feet away. Between him and it was a large open field where the horses grazed. The grass was short and covered with the dew.

A shiver ran down his back as he stared across the field. His huge balls were barely clearing the ground, and the strands of the grass were tickling the skin. The dew was cold against the flesh and the feeling was electric as it ran right to the base of his cock. His sheath started to pucker and press outwards as his shaft dropped from his belly and started sliding towards the ground.

Mozdoc let out a groan of mixed pleasure and frustration. He wanted to get someplace where he could rest, but he was not interested in playing with himself. Still his cock slid towards the ground, growing longer by the moment. Soon the head was starting to brush at the grass.

Then with a strange tug he came to a stop. He grunted and pulled with his front hooves as his back hooves seemed to be almost useless. Looking behind himself he let out a longer groan when he saw that his sack had become so huge that it had lifted his hooves off the ground.

Still his cock grew harder, blood flowing into the flesh as it rose up between his forelegs. The huge cock was at least two feet across and almost fifteen-feet in length. Even fully erect gravity was having it's way, pulling the shaft down until the flared head started to rub against the grass.

He let out a whimper, closing his eyes as his arousal came unbidden. He tried to push it away, to ignore it, but it continued to grow. Every move he made seemed to increase the feelings in his body; even the slight movement caused by his pulse was enough to arouse him more.

With a whimper he crossed his arms over his chest, and pressed them against his ample and firm breasts. He let out a low moan as his arousal increased a dozen fold. His cock started to pulse under him.

Finally he gave in, the arousal washing over him and filling his mind. He started to paw at his breasts with one hand, while the other reached out to stroke at his huge erection. He humped at the ground, rocking on his hugely filled balls as his cock burrowed against the ground. The pleasure increased by the second, his body twisting and groaning as he teased himself the best he could.

Soon it was too much. His body grew tight as he reared upwards, an whinny escaping his lips as his flared cock head exploded. Jets of thick ropey horse seamen arched from his shaft and splattered onto the ground. A dozen gallons of cum gushing onto the grass in a moment. It was followed by a another jet, and another. He could feel his balls squeezing as the semen was forced down his cock and out into the air.

It took almost half an hour before the centaur's testicles were drained of cum. It covered the ground in a huge pool, ankle deep all around him. His balls were back to a manageable size, hanging almost to his knees but no longer interfering with his legs.

Mozdoc stood in the puddle of warm seed, slowly regaining his wits from the pure pleasure of his release. It was beyond anything he had ever felt and it felt like it had been burnt into his mind. He started to walk towards the barn, but only got a few feet away from his own mess before his legs gave out. He settled onto the grass, sprawling his legs to the side to accommodate his huge equipment. He folded his arms and rested his head against them, drifting into a deep sleep

* * *

The centaur awoke as the sun started to rise over the horizon. He lifted his head, blinking his eyes clear as he tried to remember what happened the night before. His first thought was that it had been a dream, but that was dashed when he saw the drying puddle of semen covering the grass.

He struggled to his feet, his weight feeling odd about his body, like he had something strapped to his hind quarters. He looked back at his rump, dismayed to see that it was significantly more massive than he remembered it being.

At least his hunger had gone, the constant grumbling in his stomach having passed away in the night. That was one thing to be thankful for.

Mozdoc walked back towards the laboratory, feeling his testicles sway between his legs. They felt full, starting to swell once more, but they had not become unmanageable. He tried to adjust his walk to lessen the feeling, but there was not that much that he could do.

He started to rub at his shoulder, grunting as the muscles gave a twinge. He must have pulled it while he was sleeping, no surprise considering his sleeping conditions, but the pain was starting to get worse.

With a grunt he pulled open the door to the laboratory and was surprised to find Shelly on the other side. "What are you doing here?" he asked her.

She looked up at him and shook her head. "I was going to see how you slept. I see your swelling has gone down," she said.

A small smile spread out over his muzzle as his mind drifted to the night before. "Yes, it has, but it's for the best," he said as he pushed past her and headed towards the lab. "Now if you'll excuse me I want to be sure my changes to the still have been effective."

With a sigh she allowed him to walk past, then gasped. "You're changing more!" she said.

Mozdoc craned his head back to look at his equine half. "I can't really see, what's going on?" he asked, starting to feeling worried.

"Something is growing from your rump, pushing out from the muscle," she said, reaching out to gently touch the mass.

He grunted at the touch and rubbed at his chest, feeling under his breasts. There was a tingling there, growing stronger as the moments passed. "I need to see," he grunted and started down the hallway towards the infirmary, his hooves echoing down the corridor.

The centaur wedged himself into the narrow room, looking at the back wall. He tried to reach the controls, but his mass keep them just out of reach. Shelly came to his rescue, pressing the controls and turning the back wall into a long mirror.

Mozdoc shifted his body around and grunted as he saw what was happening to him. It looked like his rump had grown outwards, lifting his tail and his fairer sex onto his back. As he watched the mass grew longer, swelling outwards as the fur spread out over it.

"What's happening to me now," he said, his hand grasping at his shoulder. He groaned as he felt something starting to push up against the skin.

Shelly pressed up against him, looking closely at his growing rump. She let out a gasp as a pair of legs unfolded from the mass and reached towards the ground. "It's another horse," she said.

He moaned and pulled at his shoulder, watching as the flesh started to shift under his hand. Quickly the new mass grew, rising out from his shoulder, features starting to form as it swelled outwards into a second head.

"Oh no!" he said, both heads speaking in tandem. He could see through his new eyes. Each head looked at the other, then both turned to look at Shelly. The woman looked drawn out, her attention taken by the second body growing out from his rump.

Mozdoc shifted around, turning both heads back to look down his second equine body. It was nearly fully grown, resting on it's four hooves, and it shifted with him. He could feel the new body, control it as a part of him, because it was part of him. It finally stopped growing when it became a fully formed equine body, but without a head. Instead one body flowed into the back of the next.

He watched his body in the mirror, shifting about as he tried to move. "What am I becoming?" he asked, both heads speaking the words.

Shelly had no answer. A moment later James came into the room and gasped in surprise as he saw Mozdoc. "Holly hell, what's this?" he asked.

"The changes haven't stopped," Mozdoc said. This time the words alternated from one head to the other.

The older man nodded and ran his hand over his thinning hair. "I can see that, we need to get you into a lab. You might not want to be a specimen, but you are now. We need to get this stopped as soon as possible," he said authoritatively, then turned on his heel and marched out of the room.

Mozdoc sighed and shook his heads. "This can't get any worse," he said as he started to back out of the room. Frowns crossed his faces when he saw that a second set of breasts had grow under his first, just as large as the original pair.

He bit his tongue and said nothing as he shuffled his way out of the infirmary, his double body hard to maneuver around the hallway, but he did so, if slowly. He knew he wouldn't be able to enter that room again.

And still he felt his balls swelling, both of them. With every passing second filling them with more horse semen, the testicles expanded under the skin, and swung heavily between his legs. He hoped he could find a way to drain them before he put on another show like the night before, but he did not relish the idea of orgasming in front of his friends. Even if they didn't think of him as the man he once was.

* * *

Mozdoc shifted on his eight hooves, not enjoying the attention that James was giving him. The older man had spent the day poking and prodding the centaur in places he didn't want violated, and it was starting to anger him. The fact that his nuts had swollen to the point that they were pushing against his legs just added to his frustration.

"Aren't you done yet?" Mozdoc asked as the other man approached to take another blood sample.

James shook his head as he walked back to the centaur's second body. "No, not yet. Your blood is a bit strange, and it's not just the hormones," he said as he started to draw the blood.

Mozdoc snorted and smacked his hooves against the ground. "It seems like you've taken a pint already. How much more are you going to need?" he demanded.

"As much as is necessary to stop your changes," the older man replied as he walked back to his equipment. "What I don't know is where the mass is coming from, you haven't eaten anything close to what you weigh. Then again everything about you seems to be wrong at the moment."

Mozdoc crossed his arms under his four breasts and sighed. "That's an understatement, and I'm going to have to get off before my balls get too big. Unless you want to be knee deep in horse semen," he said.

"A semen sample would be useful, but for now I don't want you doing anything. That includes playing with yourself!" James snapped.

"What else am I suppose to do? The longer I wait the bigger I get. I'm going to have to drain it or else I'm not going to be able to walk," the centaur protested, his speech switching between his heads with each sentience.

The older man shook his head. "We can't risk that, Moz. You said you orgasmed last night and then today you grew an extra body. There may or may not be a connection, but we want to remove as many variables as we can," he explained as he continued on with his work.

Mozdoc let out a whinny and stomped his hooves, but kept his muzzles shut. Instead he started to walk around the lab, moving in a slowly circle as he practiced controlling his double body. It wasn't easy, some times he would forgot how to work his second set of legs, other times only the middle four would work.

There were only two methods of locomotion available to him. One was to step forward with all four legs on one side of his body, then follow with the others. It worked, but it felt very unnatural. The other was to move his second body forward a step, using what flexibility he had between the segments, then moving his front-most body, much like a centipede.

Neither method was terribly fast, and he would never be able to run at all. Of course with his huge testicles swinging around his hind legs he doubted he would ever want to move that fast, even if he could.

"How are you doing, Moz?" Shelly asked, breaking Mozdoc's train of thought.

He turned his head back to look at her, a small smile on his faces. She at least treaded him like a normal person. "I could be doing better," he said with both heads.

She nodded and walked up to him, stroking her fingers over his thick fur. "I understand," she said. She ran her hand up to brush through his mane. "You could use a good brushing," she said.

Mozdoc thought about it for a second, then let out a long sigh. "I might as well, there's not much else I can do here," he said.

Shelly nodded and left the labs, returning a short time later with the brushes. It made some sort of sense that she would be willing to tend to him, she tended to all the horses on the farm... like him.

He blanched at that thought as she started to brush his fur.

"Does it hurt?" she asked.

"No, I just had a bad thought is all," he said, the frown still on his faces.

She reached up and stroke the side of his original muzzle, brushing her fingers gently over the length of it. "Well don't let it get to you. Things well get better soon," she told him.

He nodded, and said nothing more as she worked the brushes through his fur. The brush caught at the fur and pulled at his skin, but it still felt good. It felt even better when she moved to his mane and tails, the brushes pulling through the coarse hair and fluffing it out.

It took quite a bit longer to cover his pair of bodies than it would for a normal horse, but that was a given, and she was careful around his huge sheath and scrotum.

"Thank you," he said as she finished her work.

Shelly smiled and reached up to pet his ears. "You're welcome hon," she said as she put the brushes away. "Do you need to go out for anything? You've been in here all day, I'm sure you have to relieve yourself."

Mozdoc thought about it for a moment, then shook his heads. "No, I don't have to. In fact I haven't needed to use the bathroom since yesterday morning."

"I see. Well, if you need anything just tell me and I'll get it for you," she said with a smile and left the lab.

The centaur let out a long sigh and shook his heads. "I'm just a horse to her."

James nodded and didn't bother to look up from his work. "Of course. She's barely adequate at dealing with normal people; your change gave her a conundrum she could only solve by treating you as an animal."

"Of course you treat me like an experiment," Mozdoc snapped back.

The older man snorted and finally looked up from his work. "You _are_ an experiment for the time being. You're not exactly fit for the world to see, and changing you back will not be easy.

Mozdoc ground his flat teeth and turned away from his friend. "I'd rather just be me, not a horse, not an experiment, but just me. No matter what I looked like," he said, shuffling his hind legs as his swelling balls began to press against them.

"You will be you once more, I'm going to do everything I can to insure it," James replied.

He let out a snort and flicked his head back. "Can you at least let me do my job? I don't like being shut in like this."

The older man sighed and returned his focus to his work. "Fine, fine, go check the stills and make sure they are operating at full capacity and the hormone levels are balanced, then try to get some sleep," he said, then waved a dismissive hand.

Mozdoc sighed and trotted out of Lab 5 and headed towards Lab 3. He took his time with the walking, gaining confidence in his movements. By the time he was at the door to the lab he was sure on his feet. He ran a check of the stills and found that everything were correct. Once he was satisfied that everything was as it should be, he moved into the unused Lab 7 and curled himself up, resting in the darkness until he fell asleep.

* * *

The sunlight growing through the lab widows brought Mozdoc awake, his eyes fluttering open as he lifted his head from his chest. He grunted and stretched out, shuffling his feet against the floor.

He found two things that were wrong: the first was that both sets of his hind legs were moving, but not touching the ground, and he could feel both his swollen testicles lifting him from the floor. The second was that he felt something slick and wet splashing over his fore hooves and down his hind legs.

Mozdoc bent his heads down and let out a gasp when he saw that the floor of the lab was covered in almost an inch of milky white semen. His first thought was that he had come in his sleep, but when he looked back at his hind quarters he realized that the situation was quite different.

His balls were huge, his hind legs over a foot off the ground and his second set of forelegs barely touched the floor. The huge scrotums had cum running down their skin, and to his surprise and horror he watched as the sperm was pushed through the tight flesh from the pressure in his balls.

"Oh no!" he moaned, grunting as he tried to move, tried to pull himself towards the door, but with no luck. He kicked his hooves at the ground, but nothing he could do was of any help. He let out a long, very horse-like, cry of frustration from his twin heads as he pawed at the floor, trying to get some movement.

A few moments later the laboratory door opened inward and Shelly stepped inside. She let out a yelp of surprise as she stepped into the pool of semen, trying to brace herself against the door. Her feet slipped from under her and she skidded around the wet floor before finally tumbling to the ground, face first into the cum as the door swung shut against her feet.

She pulled her head up, sputtering as the thick seed dripped down her face, chin and out of her mouth. She gasped and wiped her face with her sleeve, and only spread the cum around, smearing her makeup.

"What is going on?" she asked, spitting out what semen she could, but she ended up swallowing most of the mouthful.

Mozdoc blushed deeply as he motioned to his super sized balls and the semen leaking through the skin. "The pressure is too much, I'm leaking."

She craned her head back to look at his balls, letting out a small gasp when she saw what had happened to them. "Oh my god! You're huge!"

He nodded, and blushed deeply, trying not to look her in the eyes.

Shelly managed to climb onto her feet and walked carefully to her transformed friend. "What can I do to help?" she asked.

"I need to drain my balls, but James told me that I wasn't allowed to, incase it caused more transformations," he said.

She nodded and looked around at him, reaching up to run her still slick hands over his shoulders and necks. She frowned and pressed at his shoulder on the opposite side of his second head. "I'm not sure the changes have stopped," she said as she reached down and touched his chest under his second set of breasts. He jumped at the touch, the skin there was very sensitive.

Mozdoc grunted and shifted his body back, struggling to see past his lifted hind quarters and towards his distant rump. He tried to shift himself, to see more of his body, but he couldn't move enough to see.

Shelly moved down the side of his body, holding tightly to his fur to keep from slipping again in the pools of cum. When she finally got to his second hind quarters she clicked her tongue and sighed. "You're growing another body segment back here," she said.

"Damn it!" he said, slamming his hooves into the ground, splashing the cum into the air.

Shelly tried to move clear but her feet slid out from under her and caused her to fall a second time. This time she grabbed at Mozdoc's flanks to keep her balance, but only succeeded in falling against his tight scrotum.

He let out a squawk in surprise as the weight of her body fell against his balls, forcing even more semen through the tight flesh. The impact sent a jolt through his body that ran right into his sheaths, the cocks held inside surging forward and dropping from his body, landing in the cum under him with a heavy splash.

Shelly pulled away from his sack, falling on her rear in the semen. She looked back at him, her eyes focusing on the huge cock that was rapidly growing erect and pushing forward. The rear-most shaft was already pressing into the scrotum in front of it, increasing its arousal even more.

"What are you doing?" she asked, as she sat in the inch deep seed.

Mozdoc grunted and clenched his teeth. "I can't help it, your touch set me off and there's nothing I can do to stop it! I'm not sure I even want to stop it! It feels sooo good," he said, his voice echoing from both his throats, undercut by a whinny of arousal.

She scuttled back a bit and looked at him in amazement as he started to hump his rear cock against his over sized balls. His front cock pressed against his belly, just with in reach of his hands.

He bent down and started to rub the shaft with his thick fingers, ignoring the woman as precum jetted from his cock. The semen leaking from his overfilled balls increasing in volume, almost sheeting down over his flesh and onto the floor.

Shelly sat in the cum, watching the large animal in front of her pleasure himself. His body vas growing back into a third segment as he continued to jack off. She watched the body segment grow as his cocks seemed to become even harder than before.

His heads bobbed up and down, whimpering and whinnying as he pleased his own body. More precum spurted from his eighteen feet of shaft and splattered against the floor. His second cock had pushed its way under his balls and out between his forelegs.

The woman climbed to her feet as she watched him work himself. His long body tensed up as a third head arched from his shoulders and joined in the chorus of pleasure. She reached out, touching the flanks of the new segment of the body, nearly fully grown. A third cock fell from the sheath and was growing hard under his belly.

Finally Mozdoc tensed up and let out a howl as his orgasm crashed over him in an uncontrollable wave. All three of his cocks starting to spurt cum. The foremost of his shafts exploded outwards, the rope of semen arching forward and crashing into the walls of the laboratory. His second cock spurted its cum all over the floor, the final one was shot against his balls.

Shelly let out a gasp as she watched the cum blast out into the room, gurgling and bubbling over the floor and around her feet. She jumped in surprise when she realized that the level of the cum in the room was rising, rapidly filling it with more semen than she had even dared imagine.

The centaur groaned and bucked as his balls drained, his many hind legs reaching the ground, his scrotums pulsing with each jet of ropy cum that was blasted free. He completely ignored Shelly as she hung onto his farthest body to keep from losing her footing as the cum continued to rise.

It took ten minutes before Mozdoc finally let lose with the last of his orgasm and started to come to his senses. By then the room was filled with so much cum that it brushed the underside of his belly. It came over Shelly's waist and covered everything he could see.

"Are you okay?" he asked with his three heads; six breasts jutted proudly from his chest, the nipples still hard from his arousal.

"I'm fine Moz... sticky and wet, but fine," she said as she pushed her way through the cum. She kept a firm grasp on the centaur's body, using it to insure that she didn't fall.

He looked at her, then down at the cum that filled the lab. "I'm sorry, I didn't know this would happen, I didn't know I could have so much semen in me. I must drain them more often, before they become so big I can't walk," he said with a sigh.

"You could breed a thousand generations of mares with what you've produced. I wonder if you'll breed as true, or as a normal stallion," she said as she walked around to his head. Her mind returned to what she knew instead of truly dealing with what happened.

"Or a human," he said with a trio of snorts.

Shelly looked up at him in surprise. "Yes I suppose it could be, but everything else about you is equine, I'm sure your seed is as well," she said with a smile.

He let out a grunt of anger. "Then you should take your sample," he said and shoved her back. She stumbled and fell into the cum, vanishing under the thick and milky fluid. She stayed under for a moment, then broke the surface, gasping and sputtering, every inch of her covered in semen.

Mozdoc ignored her as he pushed his way to the door. He pulled at it, but the weight of the semen had locked it in place. He grunted and pulled, but it would not open.

"We are going to have to drain all of this before we can get out," Shelly said, covered in so much cum that it looked like she was made of the stuff.

He nodded his heads and looked around the room. "I can arrange that," he said and walked around the room until he reached the outer wall. He turned his back to the wall and with a heave kicked at it with his third set of hind legs. The wall cracked under the impact of his hooves. He kicked again and again, until finally the wall broke open, the thick pool of semen draining into the field outside.

Shelly gave Mozdoc a nasty look and crawled out of the hole he made. "I need to get cleaned up, you stay here until we can hose you down," she said, pulling her cum soaked clothing off as she walked out of view.

Two hours later Mozdoc was back in Lab 3, his fur still damp from the hose that had been turned on him to clean off all of the semen. He stood in the center of the lab, his arms crossed and pressed against his breasts as he glared at James. "How many bodies do you think I'm going to grow? Ten, a hundred, a thousand?"

"I don't know, it looks like every time your body has generated enough energy it tries to split you in two, like an amoeba. It's just that somehow it comes to a stop too soon, leaving you as one being. If unchecked you could grow to be miles long," the other man said, a frown on his face.

Shelly walked to them, redressed and showered. "How can you be so calm about this? We have to do something to at least stop this growth," she said.

"I'm doing my job, it's all I can do," he replied as he moved to his computer, typing quickly at the keys. "I think I might know what's causing the extra growth, why you are trying to split off as it were. I might be able to create a drug to suppress the reaction."

Mozdoc nodded his heads. "How long will it take?" he asked, the words rotating between his different muzzles.

James shrugged his shoulders as he continued to type. "The computer is working on the chemical structure. It could have it worked out in a minute, or a week. Judging from the complexity I would guess about half a day. Shelly, go to Lab 2, I want you to set up the equipment for creating the synthetic hormones."

She gave the man a short nod and rushed out of the room, eager to get to work.

He turned to look at the centaur, concern on his face. "I'm sorry Moz, I didn't know just how bad the swelling of your testicles would get. It's clear that it has nothing to do with your changes. If they become too large for you, please drain them at your convince."

"Should I keep using Lab 7, or go outside?" he asked with a smirk.

James chuckled. "By all means, use Lab 7, it's not going to be used for anything else now. Just keep it away from the mares, your semen is that of a true stallion, and it's just as potent as we were hoping for."

Mozdoc gave the man a weary smile. "At least that part of the serum is working correctly. Maybe we'll succeeded in our original goal, even if I am a freak."

"You're not a freak, Moz, and I will find a way to change you back," James said as he returned to his work.

* * *

Mozdoc paced in circles around the laboratory, his arms crossed tightly behind his back. Two heads were looking where he was going as the third was focused on James as the man tested the serum in the vial on his desk. He was putting too much force into each step, his breasts bouncing up and down over his chest, knocking off of each other like some sort of executive toy.

"Will it work?" he asked, finally allowing his impatience to be spoken.

James nodded, "It seems like it will stop the splitting effect, but there's a minor stutter in the numbers. I'm not quite sure what it is, but it could create an adverse effect."

The centaur let out a long sigh and shook his heads. "Will it, or won't it work?" he asked.

"In theory it should work, but I can't promise it, or that there will be no side effects," he said.

"Then give it to me, I do not want to have a fourth head," he said, offering his arm out to the other man.

James let out a sigh and nodded again, preparing a syringe of the serum. He held it tightly in his hand as he walked over to his transformed friend. "Are you sure about this?" he asked.

Mozdoc nodded his heads.

The other man took Mozdoc's arm in his hand, and injected the serum into the flesh. It stung as it went in, causing him to grunt and pull his arm away. He could feel the serum as it rushed through his body, creating a tingling through his blood.

"It feels weird," he said, flexing his hands as the needle was pulled free. "It's running through me, I can feel it all over," he let out a soft grunt from his mouths and rubbed his palms together. They were starting to itch.

Shelly entered into the laboratory, carrying a second vile of the serum. "Are you okay Moz? you look flushed," she asked while she handed the vial to James.

Mozdoc shook his head, the inching growing over his hands. He tried to scratch at them with his blunt fingers, but it didn't help. "Something's wrong," he said, trying to relieve the inching.

"Shit," James said as he grabbed a clean syringe and came to his friend's side. Without preamble he shoved the needle into the fur covered arm and took a blood sample.

The centaur grunted and rushed over to the nearest table, rubbing the palms of his hands over the edge. It gave him some relief, but only for a moment. He could feel his skin starting to flake and pull as he scratched at it. Finally he turned his hands around and looked at the palms, grunting when he saw red creases in the middle of each, the flesh pushing outward.

He watched in horror as the skin seemed to pulse, and aching started deep in his arms and pushed out to his hands. With a howl of pain he watched as the flesh surged out and a thick horse cock slithered out of each palm.

Mozdoc let out a deep whinny of surprise and pain as he threw his heads back. The cocks continued to slide from his hands, growing longer and thicker, the heads flaring outwards as a pair of large balls fell from each palms against his wrists. His six nipples were starting to itch now, already starting to grow in intensity.

"Do something!" Shelly snapped. "His tits are starting to swell!"

James grunted as he pounding his fingers against the computer keyboard. "I'm going as fast as I can!" he said as he looked over at his friend.

"Work faster!" Mozdoc called out with all three heads as he looked down at his six large breasts. Each nipple had swollen to twice its normal size and was starting to distort, forming the head of a horse cock.

He let out a groan and reached to grab at the growing nipples, but that only resulted in smacking his new cocks against his breasts, sending them all bouncing. The nipples continued to grow longer and thicker. Their color was changing from the dark black of his nipples to the mottled brown and white of his cocks.

James let out a grunt and spun around to look at his changing friend. "I know what's wrong. There's a secondary factor in your system, it was suppressed before but now that we've stopped the primary factor it's being enhanced. I can stop it with a minor chemical addition to the serum."

Mozdoc craned one head around to look at the older man, his others still watching his breasts. "Stop talking about it and do it!" he bellowed. His nipple cocks were huge, almost as big as the ones in his palms, and he could see the bulge of balls starting to grow from each one.

"It's not as simple as that. This _will_ suppress the factors that are causing your changes, but it will be suppressed permanently. We need that factor if we're going to change you back in less than a decade! So you can either let this change run its course, or you're stuck like this until we can find some way to turn you back!"

The centaur nodded his heads, watching as his nipples finished there transformation into full cocks. It was a relief for a moment, but the itching starting again. This time down the length of his spine, from the back of his head down to the last tail on his third body.

Mozdoc shivered as the image of himself covered head to toe in horse cocks came to his mind. Back and flank, arms and legs, all covered in uncountable cocks. He shook it off and let out a grunt as he turned all his heads to James. "Stop it, stop it now!" he bellowed.

James nodded and grabbed the second vial of serum. He dumped a red powder into it and mixed it quickly before filling a syringe with the mix. He rushed over to the centaur and plunged the needle into his quivering flank and injected it in a single motion.

It hit Mozdoc like an explosion, fire running though his veins and rushing across his bodies. It was excruciating and overwhelming. He fell to the floor in pain, landing hard on his side, his heads knocking together as he struggled with the pain. He twisted his legs tight to his body, shaking as the pain finally faded away, as did the itching.

He coughed and lifted his heads to look at his friends. "It's stopped... It's stopped and I'm stuck like this," he groaned.

"It looks like that," James said with a sigh. "I might be able to find a way to change you back, but it's going to mean understanding how your change happened in the first place. I could spend my whole life working on it and never solve the problem."

Mozdoc nodded and struggled back onto his twelve feet. "You'll find a way, you have to," he said as he rubbed his hands. Looking down at the flaccid cocks that arched from the skin, a frown crossed his muzzles and he turned away, slowly walking out of the laboratory.

* * *

Mozdoc relaxed in front of the work bench, his forelegs folded under his body so his arms were at the correct level. He worked gently with the serum in front of him, working gingerly around the cocks arching from his hands, which were strapped down to his lower arms. After almost a year he had gotten adept about working around them and keeping them out of the way.

The only time it was an issue was when they became aroused. It would sometimes happen that he wasn't careful, and of course any time the rest of his body become aroused all eleven of his cocks rose to the occasion. He had to take time out of his day to insure that he got off, or else the pressure would become overwhelming.

His concentration was broken by the buzz of the phone. He grabbed it with one hand and pressed it to his leftmost head. "Hello?" he asked, using only that muzzle. His other two heads remained focused on his work.

"Mozdoc, it's James. Good news, we finally got approval for the serum," the other man said from across the world.

The centaur smiled slightly and nodded his head. "That's good to know. I'm sorry I couldn't have been there," he said.

"I agree, but it's better than it sounds. I've starting talking to another scientist. I've described to him what happened to you, without telling them that it's not just theory. He thinks he knows how it could happen. If he's correct, we could be able to turn you back," he said, excitement creeping into his voice.

Mozdoc smiled a bit and glanced over his long body. They had all been working on returning him to human, but he was starting to doubt it could be done. There was none of his original genetic information left to use to turn him back. He had come to the conclusion that he would always be this way.

Of course not every part of him found that objectionable, in fact he had gotten used to his new form. It provided its own complications with the cocks on his hands and breasts, and his swollen balls, but he still enjoyed it. It wasn't like he didn't get a chance for some fun.

"That's great James, but let's make sure we get the patent on it first. It could come in handy," he said, all three heads lifting from his work. His palm cocks were starting to firm up as his mind wandered.

James laughed over the phone. "Of course, and your name will be the first on the paper."

Mozdoc smiled with all his heads, using one to look back at his heavy scrotums. After a month he had broken down and implanted pressure gages into the sacks to measure how much semen he had inside of him. At the moment they were brushing against his hind legs and the gages were starting to redline. "Thank you, I've got to let you go, I need to keep up with a few things. Tell Shelly of my congratulations to her."

"We still couldn't have done it without you in the first place Moz, don't forget this. You earned this as much as the rest of us. Still, you have a good day. I'll see you when we get back," James said.

"Of course, goodbye," Mozdoc replied as the line went dead. He placed the phone down and rose to his feet, walking out of the lab and towards what he called the milking room to relive himself. It was something that he looked forward to, and it he enjoyed it. He enjoyed most of his body now.

He thought back to his old self and shook his head. Even after all that had happened he felt he was better off than before. No longer was he just an obsessed chemical geek; he liked his new self, even with the minor complications.

Life, how ever odd it had become, was good.

***********

Story copyright 2006-2008 by Theo Winters, reposting and archiving are allowed as long as copyright notice and author'ss name are not removed. This story can not be published without permission of the author. Theo Winters can be contacted at TheoLionWinters (at) gmail.com.