Batman: Arkham Knight - 15 Hidden Easter Eggs, References & Secrets You Need To Find

12. Mark Hamill/Joker's Cameos

You just knew when both Rocksteady and Mark Hamill mentioned the character was done for good - Arkham Knight even opens with him being cremated - that they'd find a way to bring him back. Now, forgoing some pretty ludicrous parts of the story that are best experienced yourself (a certain underground chamber brings about a highlight of the narrative overall), Joker ends up returning as a figment of Batman's imagination, as well as essentially turning into a grinning devil on his shoulder-style character during key emotional scenes. You'll see him everywhere from atop various rooftops to the GCPD itself, occasionally verbalising things Bruce is thinking but would never say - but mostly just giggling to himself and playing on the interdependent relationship both characters have always had in the comics.