Play as Boogerman
On the Character Select screen, highlight either of the question mark boxes, hold the L Button and press B, B, Right C, Right
C, Left C, Right C. Release L and press R to make Boogerman appear in that box.

Play as Earthworm Jim
On the Character Select screen, highlight one of the question marks, hold L and press B, C-Left, C-Up, C-Right, C-Down,
C-Up. Release L and press R to make Earthworm Jim appear in that box.

Play as High Five
On the Character Select screen, highlight either of the question mark boxes, hold the L Button and press Up C, Down C, Left
C, Right C, B, A. Release L and press R to make High Five appear in that box.

Play as Sumo Santa
On the Character Select screen, highlight either of the question mark boxes, hold the L Button and press A, Right C, A, Right
C, Down C, Up C. Release L and press R to make Sumo Santa appear in that box. )

Random Character Select
At the character select screen, tap L and R simultaneously or choose any "?" square.