At the character select screen, highlight a wrestler and press L1, R1, L2, R2, L1, R1, L2, R2,
Select.

Cheat Codes:

Enter the following codes at the options screen:
 Big head mode                       R1(7), R2, Select
 Big head, hands, feet              R2(7), R1, Select
 Swelling head mode                L1(7), L2, Select
 Ring select                              R1, R2, R1, R2, Select
 All 24 rings                             L1, L2, R1, R2, L1, L2, R1, R2, Select

All players at title screen press
  R1,R1,R1,R1,L1,L1,L1,L1,R2,R2,R2,R2,L2,L2,L2,L2,SELECT