Josh saw no way out of the situation, the wolf was solid. That was until he managed to slip his leg out from underneath the wolf and put all his strength into kicking him in his musky ball-sack. He felt the wolf tense up, grab his crotch, and immediately fall over, whimpering and whining in pain. With his new freedom, Josh stood up as fast as he could and ran to the door, only to slam face first into the horse’s crotch. “I knew you preferred horses over dogs. Now come closer, I want you to drink in every inch of me.” With that, Josh was up against the horse (with an even firmer grip than the wolf), fearfully looking into his eyes. That fear turned to disgust as Josh felt the horse’s sweaty hide against his skin, the sweat immediately seeping into his clothes. The wolf wasn’t kidding about the barnyard smell, this animal absolutely reeked of a dirty barn. His body reeked of BO, sweat, and sex, all mixed in with hay, horse’s ass, and fertilizer. It was like he transformed from a sweaty farmer and fucked every farm animal there. Josh could feel his erection growing with every second near this smelly anthro. The longer he stayed, the harder it was to think straight, the more attracted to him he became. The more Josh struggled, the more of the horse’s musk stuck to him, the more aroused he became. All of this only served to turn the horse on more, as Josh watched the flat tipped, equine phallus slowly inch its way to his appropriate size (about 22 in). The shaft was as thick as a beer can almost the length of two rulers, Josh had a pretty good image of exactly what he had resigned himself to. “Don’t worry, I’ll go real slow and easy.” the horse said, ripping the clothes off of Josh with one hand.
By now Josh was overcome with horniness, the musk clouded his brain to the point where all he could think of was the cock in front of him. He didn’t care about the mutagen anymore, he didn’t even struggle, he needed to fuck of be fucked. With his rear exposed, he bent over and spread his cheeks, waiting to receive the massive shaft. The horse kindly obliged by pressing the head of his cock against Josh’s ass. Using a rubbing motion, the horse allowed some mutagen-infused precum to lubricate Josh’s ass, starting his transformation. The smell of a dirty barn and sex was now overbearing between the two of them. Josh felt his anus open up and stretch to receive the flared head of that horse cock. His ass tensed up at first, then his legs, and stopping at his feet. He felt his muscles growing as shifting as he took more of the massive meat inside his ass. His bottom half began to take more of an equine shape as the horse started to slowly go back and forth, gaping Josh’s ass. Josh came from the stimulation as he felt his erection grow with each pulse. As Josh finished cumming, he began to look like an oversized satyr, his feet changing to hooves and his hips now being wider than his shoulders. The horse then shoved his entire cock inside of Josh, making the rest of him change. The outline of the cock could be seen in Josh’s stomach as the muscles contracted and grew like his legs and ass. Soon Josh took the form of an equine without the hide, tail, or muzzle, but that was soon to change as the horse neared his climax. The horse shoved his entire length into Josh as he whinnied loudly, Josh trying to prepare for the inevitable. The musky balls on the horse flexed and contracted as cum started to fill Josh, changing him further. With the semen inside of him, his hair changed colors to a lighter brown as he developed hide, his stomach filling with seed. His face pushed out it to an elongated horse’s muzzle and his hair grew out into a long mane. His spine extended into a long wispy tail that matched his mane as his fingers turned hard and black. The horse pulled his cock out of Josh’s ass as he watched his transformation complete. All the cum that sat in Josh’s stomach turned to fat as his muscular started to diminish slightly, making him develop a muscle gut. With his transformation complete, Josh let out a loud, wet fart that stank of sex and a dirty barn. He started to get hot and sweaty from the sex he just had, so he mimicked the horse that fucked him in almost every way. The only difference was that Josh was brown, chubby, and a few inches shorter than the horse (still taller than the wolf). “Looking good, looking real good. I can imagine a few mates that would love a strong stallion like you to breed them. Or maybe you just want to stick with me for a while?” Josh contemplated what to do next. With his newly found muscles, he could easily lift a mare his size or larger. He was still horny, but was he now attracted to guys? And then there’s the wolf that tried to fuck him earlier, perhaps a bit of revenge-fucking is in order?