Mushroom

Mushrooms are recurring items in the series with numerous effects. It may refer to:
*The Mushroom Kingdom, one of the largest kingdoms in the Mushroom World, containing four stages and a level in the series.
*Super Mushroom, a mushroom that makes the characters grow bigger, increasing their strength and weight.
*Poison Mushroom, the opposite of the Super Mushroom that shrinks the players, and decreases their resistance.