Ty just smirked at Dustin, and the young boy felt himself begin to change. His young sex throbbed as it began to grow, filling him with powerful desires... his altered mind beginning to fill with images of mares, and himself at rutt... his pale young hips thrusting against the air as his cock grew... and grew... darkening from soft white to the jet black cock of an animal, a sheath growing at its base even as the tip stretches up almost to the boy's lips... his balls grow as well, covered with fur even as they swell to inhuman proportions... hanging almost down to his knees. Behind him he feels an itching sensation and turns in shock to see a tail sprouting from his rump, and another sensation alerts him to the fact that his ears are sprouting out and becoming equine... finally, his mouth and nose push out into a short approximation of an equine muzzel on his otherwise human face, giving the young boy an expression that Ty cannot help but laugh at seeing.