Mushroom Block

A Mushroom Block is an item in Super Mario Bros. 2 and their respective remakes. They are mostly found above ground in castles and World 7. They can be used to defeat some enemies, or stacked up to reach higher areas. They are required to be thrown in order to defeat bosses Tryclyde, Fryguy, and gray (NES only) and green Birdos. Mushroom Blocks can also be found in most of the red Birdos' battle rooms. Mushroom Blocks replace the masks used in Yume Kōjō: Doki Doki Panic.

Different worlds have Mushroom Blocks with slightly different patterns, as follows:

Super Mario Bros. 2

 * Wii Virtual Console manual: "This block can be used as a step or a weapon."

Trivia

 * Mushroom Blocks sometimes teleport a few pixels horizontally as they land on the ground after being thrown, usually if they would have otherwise landed in a place a number of pixels not divisible by 16 away from their starting location. This is because they are treated like terrain while idle, and sprites while carried and thrown.