There's an Easter Egg in Batman: Arkham City where there is a seemingly normal ship. If you land on the roof of said ship and use your Cryptographic Sequencer, you will be presented with a code cracking minigame (the password is [spoiler]CITYOF FEAR[/spoiler]). Completing said minigame will open a door on the boat, allowing you to go inside and find various bugs and an unconscious thug strewn about the area (it's heavily implied to belong to Jonathan Crane).