Giga Wario is, much like Mecha Mario, a secret boss. To fight him, you need to play throgh a hole game as Wario. He is the biggest boss in the game. He is the only boss that you can't sell any thing from. He has the same attacks as he did in brawl.
Strangths: He is very big
Weakness: His teeth
How to kill: First thing you have to do is run away. Then get hit by his bike attack. If this happens, he will do his laughing taunt. When that happens, Walk up to his foot. You will then have to press buttens for you to get to his head. Up there, break one of his teeth. Do this two more times and BOOM! gone.
Height: At lest 9,000 feet
Weight: 2,000 Metric Tons!