Mushroom Block

From the Super Mario Wiki

A Mushroom Block is an item in Super Mario Bros. 2 that is found in Subcon. 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 needed to defeat Tryclyde, Fryguy, and green Birdos.

According to the picture, these are the worlds the blocks appear in:

• Top left; Worlds 1, 3, and 5
• Top right; Worlds 2 and 6
• Bottom left; World 4
• Bottom right; World 7

Blocks

! Block | ? Block | ♪ Block | 4-Bros. Random Block | 99 Block | Arrow Block | Attack Piece Block | Aurora Block | Black Block | Blue Coin Block | Blue Shake King Block | Bomb Block | Bonfire Block | Bonus Block | Boost Block | Brick Block | Bros. Block | Coin Block | Command Block | Control Block | Dice Block | Dotted Line Block | Drop Block | Egg Block | Event Block | Expansion Block | Face Block | Giant ? Block | Giant ! Block | Glow Block | Grab Block | Green Block | Grey Brick Block | Hidden Block | Hint Block | Ice Block | L Block | Laser Block | M Block | Marshmallow Block | Metal Block | Minus Block | Mushroom Block | Pink Block | Platform Block | Plus Block | POW Block | Propeller Block | Pushing Block | Rally Block | Random Block | Recovery Block | Red Block | Red Shake King Block | Rock Block | Save Block | Shine Block | Simu-Block | Slow Block | Snake Block | Snowman Block | Speed Block | Spin Block | Star Block | Stone Block | Super Block | Triangular Block | Turning Block | Uncertain Block | Used Block | Vanishing Block | Warp Block | Watermelon Block | White Smile Block | Wooden Block | Yellow Block | Yoshi Block