SPOILER WARNING I think Red Hood is the Arkham Knight because people keep saying its Red hood and because The Arkham Knight unmasks to reveal that he's Jason Todd. Todd, the second Robin, was captured by Joker and apparently killed. However, he was actually imprisoned and tortured by Joker for a year. He wanted revenge on Batman for not saving him and It makes sense for the Arkham Knight to be Todd. However, I doubt it surprised most Batman fans. Jason Todd's story was an important plot in the Batman comic books. While there are differences between the comics and Arkham Knight, the basic arc of Todd is the same: he resents Batman for not killing Joker and becomes essentially a twisted, more violent version of the Dark Knight. It's no surprise that when fans were predicting the Arkham Knight's identity in months leading up to release, Jason Todd was arguably the most popular guess.