At the Story Mode game select screen press L1, Square, R1, R1, R2, Square, L1, R1, R2.
Beat the game twice.
Get two head shots in a row.
Humans and Creatures
In Single Player Mode, have a character upgrade a weapon. Also, do not have any character miss during the level.
Have all team members beat an episode with 100%.
Get two 100% head shot statuses in a row.
Enter the following during gameplay:
Up, Left, Down, Left, Down, Up, Up, Left - Big heads
L1, Left, L1, Left, R1, Right, R1, Right - Disco Mode
Up, Up, Up, Up, Up, Up, Down, Right, Up - Low Gravity
All team members must beat an episode with 100%: Defeat Leader In Single Player Mode upgrade a weapon with a character and do not miss during the level: Humans and Creatures.