? Kinoko

A '''? Mushroom' is an item that appears in the Battle Game found in the main menu of the Super Mario All-Stars version of Super Mario Bros. 3''. They are spotless red mushrooms with white question marks on them that infrequently spawn from the top pipes or are hidden in the platform blocks. There are two possible effects when obtained. If one brother is in his Super form while the other is in his Small form, they will swap forms. If both plumbers have the same form, they will swap locations.