IGN64 has posted the invincibility code for the Nintendo64 version of Mortal Kombat Mythologies: Sub-Zero. Sent to them by ClapSpot.
"Enter TDFCLT at the password screen, then select Exit and press the A Button. You should now hear a tone that tells you the trick worked. Now start the game as normal or enter a password to continue your previous game -- you're invincible!"