Metal Wario

Metal Wario is a metal powered up version of Wario, he is practically invincible and can even walk on Lava and Freezing Water, he will however start to sink in these after a while and if he goes below the surface will die. He can also be killed by falling from a great height.

Super Mario 64 DS
Metal Wario appears in Super Mario 64 DS when Wario takes his Power Flower from the red ? box in the various levels and areas of the game. He shares the exact same abilities as Metal Mario, however Metal Mario does not appear in this game; it is also unknown if Metal Mario can withstand lava and freezing water, as he never appears in levels with these hazards, unlike Metal Wario.

Mario Party 7
Wario also appears as Metal Wario when he gets the Metal Shroom from the Orb pick up spots in Mario Party 7, where he can dodge booby traps by other characters easily in one turn.

Super Smash Bros. Brawl
Metal Wario appears in Super Smash Bros. Brawl when Wario makes contact with a Metal Box. He isn't as powerful in this game and can be far more easily hurt.