Waylon Jones was born with a genetic mutation, which gave him sharp teeth and reptilian skin. He began his career when he attempted to make himself a major crime lord in Gotham City. He was defeated by Batman, and has been his foe ever since.
In the episode "Nose Mouth," Killer Croc makes a brief appearance alongside Kyd Wykkyd, Control Freak and Plasmus in Robin's dream. While Robin believes he is fighting the villains in his dream, in reality, he is actually beating up the other Titans.
- Nose Mouth (debut, cameo)
- The Inner Beauty of a Cactus (cameo)
- Killer Croc is the first non-Titans villain to make an appearance in the series. He is also the first of five Batman villains to appear in the show.
- Killer Croc appears on a punching bag in Robin's room, along with Slade and Bane.
- In the comics, Killer Croc played an essential role in the origin of Robin II (Jason Todd). However, he was not actually a Batman rogue until after the first Robin (Dick Grayson) became Nightwing.
- As usual, Killer Croc appears shirtless.
- He has a different design in the episode "The Inner Beauty of a Cactus'