Mortal Kombat 4

Alternate Costumes: rotate the screen pictures for each 
character twice, except for Sonya and Tanya. 
Rotate theirs three times.
Fight As Meat: successfully complete a group
 mode game with all sixteen characters. 
Select any character and begin a match.
Fight As Goro: successfully complete the
 game with Shinnok. Enter the character selection screen. 
Choose the Hidden icon using Run and, while holding
 it, press UP, UP, UP then LEFT to highlight Shinnok's icon.
 Press Block while still holding Run.
Fight As Noob Saibot: successfully complete the game with Reiko.
 Enter the 012 012 Kombat code in versus mode. 
Exit the match. Enter the character selection screen. 
Choose the Hidden icon using Run and, while holding it, 
press UP, UP then LEFT to highlight Reiko's icon. 
Press Block while still holding Run.
Single Player Stage Select: Enter the Practice menu. 
Select the stage prior to your desired stage. 
Start a practice mode match. Quit the match immediately.
 Start a single player game to begin at the desired stage.
Kombat Kodes:
111-111: one weapon drops onto the center at the beginning of the match.
100-100: disables throws and bone breakers.
444-444: kombatants start off with their weapons drawn.
666-666: disables background music.
050-050: enables explosive fatalities.
222-222: start the match with a random weapon.
123-123: start the match with very low health.
555-555: causes weapons to drop all over the stage.
333-333 this code no longer works in the home versions.
060-060: disables rain on the Wind World stage.
002-002: disables kombatants' ability to drop their weapons.
???-???: effects unknown.
012-012: play as Noob Saibot (Psx code... doesn't work in PC version)
020-020: enables blood rain on the Wind World stage.
010-010: disables the maximum damage limit for combos.
110-110: disables throws and maximum damage limit for combos.
011-011: play at Goro's Lair stage.
022-022: play at The Well stage.
033-033: play at The Elder Gods stage.
044-044: play at The Tomb stage.
055-055: play at Wind World stage.
066-066: play at Reptile's Lair stage.
101-101: play at Shaolin Temple stage.
202-202: play at Living Forest stage.
303-303: play at The Prison stage.
001-001: grants an unlimited run meter.
313-313: play at Ice Pit stage.
321-321: enables big head mode.