Metal Bowser is a special form of Bowser that appears in Mario Party 2. After playing a game on Bowser Land the winner heads to fight Bowser but when the character grabs his tail, he transforms into Metal Bowser and it will be impossible to lift him. But fortunately Toad offers a Star to give more power to the winner and thus, Metal Bowser is swung and thrown to the ground. Due to the impact, Bowser returns back to his normal form.
Metal Bowser also appears eventually in Super Smash Bros. Melee and in Super Smash Bros. Brawl as an opponent in Classic Mode. The player can also assume the form of Metal Bowser by grabbing a Metal Box while playing as Bowser, or during Metal Brawl.