Red Hood

Red Hood, or Jason Todd, OR The Second Robin.

Real Name: Jason Todd

Arkham Origins: Use a code for the game to play as Red Hood.

Arkham Asylum: Red Hood does not appear in the game.

Arkham City: Red Hood does not appear in the game, BUT is mentioned by Joker when you play as Robin in the Joker's Funhouse Challenge Map.

"You? Didn't I Kill You Already? Oh Well, There's Always A Second Time."

(Quote May Not Be Exact)   -Joker

Arkham Knight: Red Hood might be the Arkham Knight.