- This article is about the item in the Mario Kart series. For the orb in Mario Party 6 and Mario Party 7, see Metal Mushroom Orb.
Upon being used, the Heavy Mushroom turns the driver metallic, resembling the effect of a Metal Box, as well as turn the kart monochromatic. In this state, the user is so heavy that they knock over any rival kart they touch, bringing the rival to a stop. The effects of the Heavy Mushroom wear off after approximately five seconds.