The "Mushroom" is an item for Mario Paint Composer.

There are also stars, game boys, planes, swans, dogs, cats, human heads, Piranha Plants, masks, cars, hearts, coins, ghosts, Yoshis, ships and Fire Flowers.

The "Mushroom" was one of the items found on the original Mario Paint game. It is used as percussion mainly in songs as it makes a sound similar to that of a drum.