Tattoo (1987 TV series)

In the beginning of Planet of the Turtleoids, Part 1, the come across a large man who looks like a tattooed sumo wrestler breaking into a pet shop. They confront him, and he speaks in broken English and growls, and says his name is Tattoo and he wants to go home. They scuffle for a bit, with Tattoo having the upper hand throughout most of the battle. Tattoo grabs a power line to attack with and accidentally wraps it around him, electrocuting him. Rather than killing him, however, he regresses back to his true form - a hamster. The Turtles surmise that and  had been experimenting with  again, and that "Tattoo" was a hamster from that very pet shop, and only wanted to return to his cage.