How To Get Fritz Von Erich:

You must successfully complete career mode with Kerry Von Erich to unlock the wrestler Fritz Von Erich.



How To Get Jimmy Hart:

You must successfully complete career mode with any 'Loved' legend to unlock Jimmy Hart.



How To Get King Kong Bundy:

You must successfully complete the Southeast Territory (in career mode) to unlock King Kong Bundy.



How To Unlock Captain Lou Albando:

You must successfully complete career mode with any 'Hated' legend to unlock the wrestler Captain Lou Albando.



How To Unlock Extra Arenas:

You must successfully complete the game in career mode to unlock the following arenas in exhibition mode:

Back Lot, Gym, Beach Resort, and Casino.



How to Unlock Ivan Koloff:

You must successfully complete the vs. tourney mode to unlock Ivan Koloff.



How To Wrestle As Dory Funk:

You must successfully complete career mode with Terry Funk. Once you do this you will unlock Dory Funk.



Play as David & Michael Von Erich:

To unlock David & Michael Von Erich, complete career mode with Kevin Von Erich.

Source: Nintendo Power



Play as Mr. Fuji:

To unlock Mr. Fuji, win the tag team belt in tournament mode.

Source: Nintendo Power



Play as The Rock-n-Roll Express:

To unlock Robert Gibson & Ricky Morton, win a Tag Team Tournament.

Source: Nintendo Power



To Wrestle as Sabu:

You must successfully complete the career mode with The Sheik in order to unlock Sabu.



Unlock All Wrestlers:

At the Main screen, Press UP UP DOWN DOWN LEFT RIGHT LEFT RIGHT Y Y X. If you enter it Correctly, A screen will pop up saying you have new wrestlers. You can Save them.