War of the Monsters Easter Egg - Secret Character

First beat twisted metal black as sweet tooth. Then use the same memory card for your war of the monsters save game. A message will appear saying "Mecha sweet tooth unlocked" (or something similar). If you use the character with the flaming head then his costume 4 will be mecha sweet tooth (because his head is on fire too) occasionally, while you are playing as him you will hear his traditional laugh.