The Gust Bellows is a weapon from The Legend of Zelda: Skyward Sword, and it was introduced as an item in Super Smash Bros. for Nintendo 3DS/Wii U. It was revealed on Sakurai's Miiverse page and simultaneously on the Smash Bros. website.
The Gust Bellows can be used to produce powerful wind blasts that push opponenents away. When someone drops it, the gusts run wild. The wind it produces does not deal any damage, though. The Gust Bellows will not make opponents flinch, making it a good edgeguarding weapon. However, the Gust Bellows will run out of ammo after being used for a short period of time.
Unleash gale-force winds upon your foes to blow them far away. Unfortunately, it's just air, so it won't do any damage except maybe mess up their hair. Dropping or throwing it will cause it to spin around, blowing air everywhere. Don't blow yourself outta the fight!
Wii - The Legend of Zelda: Skyward Sword (11/2011)