Box as a Bear
At the Main Menu press Right Square Right Triangle Right Circle Right X. Then select any boxer.
Big Head Mode
At the Main Menu press Left Circle Left Triangle Left Square Left X.
Between fights when given a choice to hit the heavy or speed bag hold L1 L2 R1 R2.
Press R1 R2 X during a match.
Knock your opponent down in Career Mode while simultaneously pressing Start. Choose to lose the fight and if timed correctly the loss will be placed on your opponent.
In Career Mode create a boxer with the h3 psirules. Exit out to the Main menu then load the boxer. He will have 100 of everything 7'5'' and 250 pounds.