Waylon Jones, also known asΒ Killer Croc, is an alligator-wrestler and sideshow-freak turnedΒ Gotham CityΒ mobster, sewer-dwelling super-criminal and enemy ofΒ Batman. He is motivated due to having been born with a rare mutation that caused him to have reptile-like skin, leading to a lifetime of abuse and prejudice which drove him to madness. In his early appearances, this manifested as tough, crocodile-like skin, but over the years he has slowly taken on more crocodilian features, essentially becoming an anthropomorphic reptile.