Most of Batman's rogues gallery is comprised of mentally deranged killers, or diabolically smart criminal masterminds. Most are generally human. But one stands apart-the massive freak of nature known as Killer Croc. Born as Waylon Jones, Croc has a rare genetic condition which gives him a crocodilian appearance. Raised by an abusive aunt who mocked his deformity, he eventually ran away and joined the circus, becoming a sideshow carnival attraction, where patrons could come and gawk at the freakish strongman called "Killer Croc." Croc eventually departed for Gotham City, where he began a life of crime-one which brought him into regular conflict with the Dark Knight.