Giga Bowser (Giga Koopa (ギガクッパ Giga Kūppā)?) is a gargantuan version of Bowser, making his debut as the main antagonist of the Adventure Mode in Super Smash Bros. Melee. He also appears as Bowser's Final Smash in Super Smash Bros. Brawl, Super Smash Bros. for Nintendo 3DS and Wii U, and Super Smash Bros. Ultimate.
In Melee, he appears as a boss. To fight him, Adventure Mode must be cleared on Normal or higher in 18 minutes or less. He will appear after Bowser is defeated. Defeating him without using a continue rewards you with the Giga Bowser trophy. He also appears in Event 51: The Showdown with Mewtwo and Ganondorf by his side. He can be controlled by using an Action Replay for the Gamecube or using a mod hack for Switch.