"Before we continue, I'll undo my previous transformations." Jeanie said. Marcus made a long relief sigh.
Jeanie snapped once and Marcus big tongue became normal again, at her second snap Marcus' testorone level went down and his anormal muscles and body hair reduced to an average level. Her next snap made Marcus' genitals to shrink and now he looked like a regular teenager. Finally, her last snap made Marcus to turn back to his old 12 years old boy self.
"Thank you! I feel way more comfortable now!" Marcus said. "Now, if you can give me my clothes back..."
"I had forgotten you're so small!" Jeanie said. "I think I like you more in your last stage."
"What do you mean?" Marcus said but he felt a sudden growth spurt that turned him back to his 16 years old version. His sudden change and new height made him to lose balance and he fell on the floor. "Why did you make me old again? I was happy like I was before!"
"You look good, Marcus! What else do you want to know?" Jeanie said. "Also, my next transformation will need a male who could release his DNA."
Despite Jeanie's polite way to say it, Marcus knew she was referring to his capability to cum which he knew he only can make after he hits puberty, just like he was now.
"More transformations?" Marcus said. "What else do you want to know? Conception? Fertility?"
"I don't know what are you talking about!" Jeanie said with a smile on her face. "I mean this!"
She clapped her hands and a purple gas surrounded Marcus.
"What's this?!!" He yelled but he shut up when he saw how the gas was getting inside him through his mouth. He closed it, but the gas was entering through his nostrils and ears.
He tried to cover his ears with his hands but when he touched them he felt something unusual. His ears were longer than before, also they were getting pointy. Then he touched his nose and he realized that it and his mouth were getting longer like a muzzle.
"You're turning me into an animal!!" Marcus said and he realized how much his mouth had changed. It was bigger than before, his tongue was longer and heavier and his teeth were reshaping too.
"Yes." Jeanie said. "I want to see how different DNA is from different male species. I decided to begin with one of my favorites, a horse."
"Horse?!" Marcus yelled, he was getting some troubles to talk know. "Will I turn into a horse-iiii!!"
He touched his face and he felt how it had completely turned into a horse head. His ears had finally moved up his head and his eyes changed their position. He saw how quickly he was bulking, his muscles were changing from human to horse. He looked way more stronger than any bodybuilder right now.
"Pleeease! Stop iiit!!" He managed to yell between whinings but Jeanie ignored him. His arms and legs were turning into horse legs and his hands and feet were doing the same into hooves. Now, he looked like almost like a bald horse. But it quickly changed as he began to grow fur all over him. A long mane appeared on his longer neck and a spine movement made appear a horse tail with hair.
"Nooo-iiiih!" It were Marcus last words before he lost his capability to talk and he finally turned into a full horse.
"Well, it's finally done, Marcus!" Jeanie said. "I told you, you look so good, a great stud for sure!"
She helped him to stand up. Being on four were completely weird to Marcus but he knew it was useless to try to stand up in two legs. He realized he can't feel his fingers anymore, but he discovered he can move his new tail.
"Uhm..." Jeanie said. "Something is wrong... let me see... head, hooves, fur... tail... muscles... I'm forgetting something."
She moved around Marcus to look him better.
"Maybe it's your butt crack..." Jeanie said and she put her hand over Marcus' bigger horse ass. She opened it and looked "No, it's there under your tail."
Marcus can't show it but in his mind he was completely embarrassed of how she was touching his ass. It was difficult to realize it had changed, but it was harder if someone was looking at it.
"I know!" Jeanie shouted. "How I didn't see it before!"
She kneeled and said. "You can't be a stud with those human genitals! You need a horse dick!" She snapped and some of the purple gas appeared around her hand and flied directly to Marcus' human cock. It entered through his urethra and Marcus felt a sudden arousal while it's dick was growing from 4 inches to a monstruous 20" long. It got a sheat on its base and and ring in the middle of the tube. Jeanie looked amazed how Marcus' mushroom changed into a flat glans. Finally its skin color got darker. Marcus can't hold his arousal any more and he released a dose of cum from his new tool.
"Hey! Don't do that without telling me!" Jeanie complained. "I want to collect your DNA! Oh well, I haven't changed your balls so I assume that was human DNA instead of horse one."
She snapped her fingers and Marcus' testicles reacted inmediatly and turned into horse balls.
"Now, I will need a dose of your horse DNA so, please, shot it in my hand!" She smiled as she put her hands under Marcus' dick tip.