Mechagodzilla is a alien cyborg created by the Aliens from the Third Planet of the Black Hole and first appeared in Godzilla vs. Mechagodzilla (1974) and Terror of Mechagodzilla (1975). He is considered one of Godzilla's main rivals, due to his extreme power. He is armed with a large variety of weapons, such as finger, knee, and toe missiles, the ability to shoot lasers out of his eyes, and a laser out of his chest. Mechagodzilla can also shoot rocket jets out of his feet, allowing him to fly. It can also spin its head to make a shield. Different incarnations of Mechagodzilla include Mechagodzilla 2, Super Mechagodzilla, and Kiryu. The first Mechagodzilla's video game appearance is in the Wii version of Godzilla: Unleashed.
Mechagodzilla first appears in Godzilla vs. Mechagodzilla (1974), disguising himself as Godzilla, having the name Fake Godzilla. Anguirus is not fooled by Fake Godzilla and attacks it. Mechagodzilla defeats Anguirus and proceeds into Japan, causing destruction. The real Godzilla shows up and reveals Fake Godzilla to be Mechagodzilla. A fight ensues, having Godzilla being wounded and Mechagodzilla in need of repairs. Later, the humans call out the lion god, King Caesar, to aid them in the fight against Mechagodzilla and the Aliens from the Third Planet of the Black Hole. King Caesar awakens and fights Mechagodzilla on an island. At first, King Caesar has the advantage, but later, Mechagodzilla manages to take the advantage until Godzilla shows up. Godzilla and King Caesar team up to destroy Mechagodzilla. After having King Caesar knocked out, and shooting Godzilla with multiple darts, Mechagodzilla starts to fly away, until Godzilla turns himself into a magnet (because he was struck by lightning after his first fight), and managed to pull Mechagodzilla towards it and manages to rip its head off until it falls off. 1 year later, Mechagodzilla was reconstructed in Terror of Mechagodzilla, and teams up with Titanosaurus, a dinosaur found in the Pacific Ocean. They both fight Godzilla who is alone, tipping the odds into Mechagodzilla's and Titanosaurus's favor. Godzilla manages to defeat Titanosaurus by shooting him with his atomic breath and he falls into the ocean (Titanosaurus's fate is unknown) and Mechagodzilla's head is ripped off again, only this time, he is still able to fight, but still unable to defeat Godzilla. Finally, Godzilla defeats Mechagodzilla and walks away into the ocean.
Mechagodzilla was going to appear in Godzilla: Save the Earth, but Mechagodzilla 2 and Kiryu were already in it, so Atari scrapped it, but it does appear in Godzilla: Unleashed as a Wii exclusive. Though it is unable to fly, he can still shoot lasers from his eyes, and fight properly. He is even able to fire a flamethrower out from his mouth (in Godzilla vs. Mechagodzilla, when it was disguising as Fake Godzilla, the Aliens from the Third Planet of the Black Hole put a flamethrower in its mouth, treating it as Fake Godzilla's atomic breath to mimick Godzilla's atomic breath.) He even appears in Godzilla: Monster of Monsters, which was a 1988 NES video game where he appears as an enemy. He even appears in the 1990 Game Boy game simply titled "Godzilla", and he has a speed slightly slower than Godzilla's. He also appears in the US version of the 1993 SNES video game "Super Godzilla" (the Japanese version featured Mechagodzilla 2), he first appears as Fake Godzilla, then after being punched once, he turns into Mechagodzilla.