Waylon Jones (a.k.a. Killer Croc) is a member of the Batman's rogues' gallery. Born with a variant form of epidermolytic hyperkeratosis, a rare congenital skin disorder, Waylon went from wrestling alligators to trying to muscle his way into Gotham City's criminal underground. Experiments performed on Croc have made him more lizard-like over time.In the animated series The Batman (Kids' WB!), Croc's background was never fully explained. In this series, Waylon was more like a human/reptile hybrid; he even had a thick, powerful tail.