Transformers: Beast Wars Metals 64 Codes -

Ravage and Tigatron:
Select vs. or arcade mode. Highlight Cheetor, then hold Z and press A at the character selection screen. Then, press Left or Right to go through his colors to get to Ravage and Tigatron.

Starscream:
Select vs. or arcade mode. Highlight Waspinator, then hold Z and press A at the character selection screen. Then, press Left or Right to go through his colors to get to Starscream.

Black Arachnia:
Select vs. or arcade mode. Highlight Tarantulas, then hold Z and press A at the character selection screen. Then, press Left or Right to go through his colors to get to Black Arachnia.

Original Rattrap:
Successfully complete the game, including defeating Megatron X. Select vs. or arcade mode. Highlight Rattrap, then hold Z and press A at the character selection screen. Then, press Left or Right to go through his colors to get to his original appearance.

Defeat Megatron X:
Press C-Right to keep firing your gun until you get a Energon Strike. Transform into vehicle mode. Then transform into beast mode and keep pressing C-Right rapidly until your Energon bar is filled. Get close to Megatron X. Repeat this you defeat Megatron x twice.

Another advantage happens when both of you shoot something at the same time, after you fire block. Your shot should hit and his should do minimum damage.

Metal Megatron:
Defeat Metal Megatron in arcade mode to unlock him as a playable character.

Hint: Easy win:
For an easy win, transform as in vehicle mode. Run/fly around the arena and keep pressing C-Left or C-Right to use good weapons. Then, when your enemy is half way down in HP, turn into robot mode, hold C-Left for about fifteen seconds, and release. Your character should do a strong blast and should defeat your enemy easily.

Glitch: Robot watcher:
Play on the Ice stage, and look at the background closely. You should see a robot that is watching you. Note: This does not happen very often.