UFC: Undisputed 2010 Easter Egg - Shaquille O'Neal in the Octogon

enter the code on the main menu
360:Right, Up, Left, Right, Down, Left, Up, Right, Down, Left, X, Y, Y, X, Start.

PS3:RIGHT, UP, LEFT, RIGHT, DOWN, LEFT, UP, RIGHT, DOWN, LEFT, SQUARE, TRIANGLE, TRIANGLE, SQUARE, START

When the code is entered correctly, a message will pop up on screen telling you have unlocked a new fighter. Then head into an Exhibition bout and you will find Shaq among the heavyweight contenders.