Wario Waft
The Wario Waft is Wario's Down Special Move. It becomes more powerful as time passes, ranging from a tiny "poot" (which knocks opponents down. but delivers no damage) to a massive explosion (which has high knockback and damage). It was first revealed in Super Smash Bros. Brawl's first trailer, where the move created a large explosion, complete with a mushroom cloud. It seems that the move cannot have such power in the actual game. When the attack is fully charged, Wario will glow red.
A fully charged Wario Waft from normal Wario does 40% of damage. He also flies into the air a distance that is nearly unrivaled by any other recovery move. While he's Wario-Man, the Wario Waft can do 78% of damage even if it isn't charged up, has unimaginable power, and is practically a One-Hit KO.
Origin
Wario has been known to fart alot. He also used other attacks in the mario universe that involve farting.