Real Name: Waylon Jones
Occupation: Criminal
Marital Status: Single
Base of Operations: Gotham City
Height: 7ft 5in
Weight: 686 lbs
Eyes: Red
Hair: None
First Appearance: Detective Comics #523 (February 1983)
Created By: Gerry Conway, Don Newton

Waylon Jones was born with a medical condition that caused him to grow progressively more like a crocodile. In the comics his intelligence level has varied from competent schemer to berserk monster.

Jones is one of the few black supervillains. In his original appearances, he resembled a powerfully-built black man covered entirely in green scales. However, his disease has slowly robbed him of all identifiable human traits.

Killer Croc was summoned by a strange paranormal force to break out of Arkham Asylum and make his way to the Louisiana swamps. Batman followed him there only to find that the mysterious force was actually the Swamp Thing, who offered Croc a place in the swampland where he could finally give in to his animal side and live free from human persecution.

While he was working with Hush, he was infected with a virus that greatly increased the rate of his devolution, causing him to be less intelligent and more monstrous.

Killer Croc attempted to cure his condition. When the doctor failed, Croc devoured her despite her efforts.