Cadobbit

The Cadobbit was a mutant creation of Dr. Animo's which appeared in the Ben 10 animated series episode Can I Keep It?

Description
A hybrid fusion of cat, dog and rabbit, the Cadobbit shared attributes from all. Although a small creature only a couple of feet in length when first encountered, after Animo tormented it using a remote-controlled electronic device it grew into a large monstrosity twice the height of Ben Tennyson and many times his weight.

History
First coming across the Cadobbit outside a petting zoo, Ben was immediately smitten with the little critter. Despite being told by Grandpa Max that he couldn't have a pet, Ben snuck the animal aboard the Rustbucket, and kept it hidden from Max and Gwen.

Later however, Dr. Animo activated his remote control, infuriating the Cadobbit and causing it to grow to enormous size before commanding it to attack an unwitting Ben. Transforming into his Grey Matter mode, the boy noticed the transmitter attached to the Cadobbit's ear and managed to dispose of it. This caused the Cadobbit to once again become docile, and allowed Ben to chase off Animo.

At the end of the episode, the Cadobbit wandered off into the woods to live a peaceful life, despite Ben trying to get Grandpa Max to allow him to keep it.