As Jen protests weakly, she is dragged into the petting zoo, where small furry animals are located. Keeping her head down, Jen meanders around, listening to the delighted squeals of her friends. As Jen walks along, she accidently bumps into someone. Muttering a hasty "I'm sorry about that" Jen gets up off the floor and bends down to help the person. As she does so, she accidently turns her head and spots a small rodent-like creature in her periphial vision. Looking at the ID tag, she has just enough time to identify it as a chinchilla before the changes start.
First, Jen's clothes disappear, leaving her completely naked. Then, an itching sensation sweeps over her, soon covering her whole body. As she looks down at herself, she sees tiny grey and white hairs start poking out of her skin. The fur starts at her feet and moves up. As the fur sweeps over her breast area, Jen can't stop herself from stroking it, and shuddering a little at the pleasant sensation. As the fur finishes it's path over her body, Jen feels a strange feeling at her hands and feet, and looks down to see them turn into paws.
Feeling a strange tugging feeling at the base of her spine, Jen twists around to see a furry rodent-like tail sprout out of her. Swishing the tail around, Jen feels an alien sensation wash over her as endorphines from the muscle use are released.
As Jen reaches up to feel her face, she finds that her ears have migrated to the top of her head and have rounded out. Her face pushes out into a rodent muzzle and her eyes have become black and beady. Feeling a pressure on her back, Jen is pushed down to all fours, although she finds that she can still assume a bipedal stance, albeit only while standing. With a few more cracks and pops, and a shrinking down to the size of the rodent that started this, Jen's transformation into a chinchilla has completed.
(Added because of a lack of chinchilla stories)