Jen went out to the field where she had changed the day before, if was still covered in cum, dried by now. She walked out and looked around.
"Maybe I can find some more neat changes." She said.
Just then she saw something wriggling toward her, she looked and saw that it was a snake, a python. She remembered her neighbor talking about loosing it last week, she sat down and spread her legs, it would get there anyway.
"I wonder what you'll do." She smiled.
She felt the python slide into her pussy, it coiled inside of her and then was absorbed. A few moments went by, then she felt a strange feeling in her penis, it started to writhe, it grew another foot, now 7 feet long, she tried to control it but she couldn't.
"Oh shit, what did I just do?"
It continued to grow, longer as it swung, stretching out to 10 feet. It hit the ground and Jen moaned with pleasure as it slid back and forth continuing to grow, cumming again and again. It stopped at a full 16 feet, and she regained control of it's movements.
She made it slide to the left.
"Wow, I can really have fun with this!"
She coiled her newly modified penis, rubbing it against herself, cumming repeatedly. She was so busy that she didn't notice the horse that entered the field. He was a Clydesdale, a massive 3300 pounds of flesh, his member stiff with excitement, smelling the juices of Jen's pussy, she looked up and scrambled but the horse rammed her to the ground.
"NO! NOT YOU!" She screamed as the horse shoved his muzzle into her pussy, her legs spreading wide as the beast pushed further. Her penis wrapped around it's body, betraying her wishes, she screamed as it reached it's front legs. She could feel the bulk of the creature inside of her, her legs flailing in feeble protest as the horse reached it's penis, she felt it slide in.
"WHY DO THEY ALL HAVE TO BE GUYS???" She screamed as he finally slid his tail in, it's mass diminished inside of her, she stood up shaking with fear and excitement to see what changes she would have. She felt her body shifting, she was growing taller, but when she looked down she screamed, she saw another pair of legs growing in, her feet changing into hooves as her lower body grew longer, she could feel the horses member grow in above her first, her balls enlarged a little to accommodate it's semen. Her body still growing she tried to move, but her new lower body didn't respond. She saw the ground getting farther and farther away.
"How big am I going to get?" She cried.
She finally stopped growing, her mostly human half sat 7 feet off the ground, her elephant penis massive even on her Clydesdale frame, she forced it to wrap around her powerful horse chest.
"Great, just great, now I'm a centaur. How do I get in the house like this?"
Jen's question was soon answered when she got to her house.