Batman: Arkham City - Armored Edition Cheats For Wii U
Chose a saved game, on menu screen press Left, Left, Down, Down, Left, Left, Right, Up, Up, Down. You'll hear a bat flutter sound. Then chose to continue your game and you will come to the costume select screen.
Big Head Mode
Equip the Cryptographic Sequencer. Then, hold ZL and ZR. Move the left analog stick clockwise, and the right analog stick counterclockwise. After a while, your fists and head will grow.