If spoilers aren't your thing, you best navigate away now. However, if you wake up in the morning to a hand-built, spoiler-dispensing machine that fires tasty, yet-to-be-revealed morsels directly into your awaiting mandibles, then hit the jump to find out Batman: Arkham City's fourth and final playable character.
The folks over at ArkhamCity.co.uk spotted a familiar name in the updated trophy list for the game. The proof is (as it is always deliciously-positioned) in the pudding, which you may feast on below.
4th Playable Batman: Arkham City Character Revealed [ArkhamCity.co.uk]