Giga Bowser

Giga Bowser (ギガクッパ, Giga Kuppa, Giga Koopa in the Japanese version) is a gargantuan version of Bowser. To fight him, you must clear Adventure Mode on Normal or higher in 18 minutes or less. Then he'll appear after you defeat Bowser. Defeat him without using a continue and you get the Giga Bowser trophy. He also appears in Event 51: The Showdown. Some things that separate Giga Bowser from Bowser are:

• Approximately 1.7 times larger
• Infinite flame breath
• More height gained from Fortress
• Cannot be grabbed
• Forward tilt sets opponent on fire
• Down smash freezes opponent
• Forward smash creates a large explosion
• Neutral aerial electrocutes opponent