Bucket

A bucket is an object that appears within several games in the Mario franchise, often serving a minor role that varies widely between appearances. It first appears in the Japan-exclusive game Mario & Wario as a central game mechanic; among its other appearances, it also plays a relatively minor role in the Yoshi's Island series of games.

Mario & Wario
In Mario & Wario, the bucket is among the objects used by Wario to obstruct the vision of the protagonists - Princess Peach, Mario, and Yoshi - by dropping them on their heads; Wanda the fairy has to guide the blinded heroes through each of various stages. The Bucket itself is used in the very first stage of the game, Yōsei no Mori, and features Mario's "M" insignia when upright; when turned upside-down while over a character's head, the "M" becomes Wario's "W," referencing his "power" over the character. Later stages outside of the EXTRA stages will feature multiple different objects.

Yoshi's Island series
Buckets make their debut in the Yoshi franchise in Super Mario World 2: Yoshi's Island. They tend to appear in fort or castle areas and levels, beginning with Burt The Bashful's Fort. These buckets can be found hanging on walls or ceilings, and the Yoshis can knock them down by throwing an egg at them. Knocking down these buckets may produce coins or enemies; some levels have buckets positioned over a body of water or lava, and knocking them down allows the Yoshi to cross that area using the bucket until they reach the other end. Buckets also appear in Yoshi's Island: Super Mario Advance 3, Yoshi's Island DS and Yoshi's New Island, serving the same role. There is also a gold bucket variety that doesn't fall down when hit.

Super Mario RPG: Legend of the Seven Stars
A bucket appears in Moleville in Super Mario RPG: Legend of the Seven Stars, where it serves as a hidden warp to the Midas River. If the mole girl standing on top of it is given a Carbo Cookie, she jumps off of the bucket, granting access to the river and the Midas Waterfall Course.

Paper Mario
The bucket (alternatively known as the Marvelous Bucket ) is a key item in Paper Mario, where it can be obtained from the mayor of Shiver City after getting the Scarf from Merle. After Mario gives each of the items to the snowmen in Shiver Snowfield, the passage to Shiver Mountain will open.

Other apperances
The book Mario and the Incredible Rescue, has Mario, Luigi, Yoshi and Toad fighting Wario in Booster Pass. The fight has Wario driving his plane, as he throws Buckets down at the gang. Mario and Yoshi defeat him by jumping up to his plane and placing a Bucket on his head, blinding him and causing him to loose control of his plane and spiral out of view.