Jenny pushed the door opened and look into the horse stall and saw Old Carly on the floor. It sounded like she was in pain, but soon her nays turned into moans. Moans of pleasure.
Jenny watched as Carly seemed to shrink a little. Her front legs became human-like arms and her hooves became hands with thumbs. Her legs began its metamorphosis into human-like legs. Carly's ass then started to change shape. Instead of the huge horse's ass she had, it has shrunk down into a big human-size ass. In fact, she had a gorgeous human-like ass. Her black horse's vagina moved into its new place between her now human-like legs. Her belly started to suck in as as she started to gain a woman-like figure. Next two mounds pushed out of Old Carly's chest. And even though Carly was old in horse years, it seemed like she was going to be young as her breasts were the ones an 18-year old girl would be proud of.
She stood up. She was still horse-like with her head pretty much unchanged, even though her mane was more like human hair now. She still had her coat of fur and her horse's tail. Carly was now gaining knowledge in her head on simple human things such as talking.
She looked over at the transformed Jenny and said, "Now I can ride you! And once I'm tired with you," she picks up the gun that Jenny had dropped earlier, "I'm going to shoot you!"
Jenny was filled with fear!