Killer Croc is a fictional supervillain appearing in American comic books published by DC Comics, commonly as an adversary of the superhero Batman. The character was created by writer Gerry Conway and by artist Don Newton. The character's first appearance was a shadowy cameo in Batman #357 (March 1983), which was also the first appearance of Jason Todd. Killer Croc belongs to the collective of adversaries that make up Batman's rogues gallery.