Clad in shackles and broken chains, the overtly saurian Killer Croc is a towering behemoth with massive tooth-filled jaws. Killer Croc originally has an atavistic condition which afflicts him with comparatively superficial reptilian attributes, although further mutations transform Croc into a brutal monster with dense armor-like scales, heightened strength and reflexes, and a regenerative ability. Croc’s attempts to reestablish some of his human qualities are met with frustrating failure. When battling Killer Croc, Batman offsets the former’s overwhelming strength and durability by exploiting Croc’s diminished intellect. In Arkham City, Killer Croc relocates to the sewers of Gotham, establishing them as his primordial lair, killing any trespassers.