Turok 3: Shadow of Oblivion (N64)

Codes
At the Secrets screen, enter any of the following:

Elk, Elk, Elk, Elk, Elk, Elk - Credits

Cougar, Horse, Elk, Salmon, Cougar, Hawk - Pen and Ink Mode

Raven, Salmon, Eagle, Bear, Lizard, Rabbit - Invincibility

Owl, Bear, Owl, Insect, Hawk, Owl - All Weapons

Salmon, Elk, Bull, Snake, Eagle, Salmon - Unlimited Ammo

Frog, Elk, Horse, Dragonfly, Wolf, Rabbit - Warp Level 1

Owl, Owl, Horse, Elk, Elk, Elk - Warp Level 2

Owl, Rabbit, Bear, Insect, Frog, Cougar - Warp Level 3

Bear, Horse, Raven Eagle, Horse, Coyote - Warp Level 4

Bear, Dragonfly, Horse, Bear, Frog, Elk - Warp Level 5

Lizard, Dragonfly, Bull, Bear, Wolf, Eagle - All Keys

Lizard, Elk, Eagle, Owl, Salmon, Horse - Headless

Lizard, Salmon, Insect, Salmon, Wolf, Dragonfly - Gouraud

Defeating Oblivion
Many have come to me, asking for a way to defeat Oblivion (in its large monster form). You can defeat Oblivion by shooting his hands (when he is using them to attack). You must also make sure that the fist that you shoot is the one that he is attacking with!

More modes
At the Secrets screen, enter:

Snake, Bull, Snake, Frog, Bear, Elk - Mannequin mode

Horse, Eagle, Snake, Cougar, Insect, Salmon - Stick Man mode

Frog, Frog, Salmon, Insect, Wolf, Cougar - Tiny mode