Rotating Block

Rotating Blocks, also known as Spinning Blocks, Turn Blocks, or simply Blocks, are yellow blocks with eyes that first appear in Super Mario World. When hit from below or the sides, they briefly spin around, allowing Mario or other characters to pass through them.

Super Mario World
In Super Mario World, Rotating Blocks replace bricks from previous Super Mario games and share most of those blocks' attributes. Normal Rotating Blocks spin around for a short time when hit from beneath or attacked as Caped Mario (or Caped Luigi), but some act as Prize Blocks and reveal an item. Super Mario can destroy normal Rotating Blocks with a Spin Jump from above. Chargin' Chucks can also destroy Rotating Blocks by charging into them. Also, enemies such as Koopa Troopas and Goombas may hide in Rotating Blocks, and break out to attack Mario once he approaches him.

Super Mario Maker / Super Mario Maker for Nintendo 3DS / Super Mario Maker 2
Rotating Blocks appear under the name "Block" in Super Mario Maker, Super Mario Maker for Nintendo 3DS, and Super Mario Maker 2. Rotating Blocks replace Brick Blocks in the Super Mario World style. To be consistent with the other styles, Rotating Blocks are affected by P Switches instead of Empty Blocks, unlike in Super Mario World. In Super Mario Maker 2, if the player presses a P Switch, any Ice Blocks with a coin frozen inside temporarily become frozen Rotating Blocks (resembling the Ice Blocks' design from the original Super Mario World). However, when hit from below or the sides, they do not spin.

Super Smash Bros. series
Turn Blocks appear in the Super Smash Bros. series in Melee's Yoshi's Island stage (in Super Smash Bros. Melee, Super Smash Bros. Brawl, Super Smash Bros. for Wii U, and Super Smash Bros. Ultimate) and in the Super Mario World style of the Super Mario Maker stage (in Super Smash Bros. for Nintendo 3DS / Wii U as DLC, and Super Smash Bros. Ultimate), working as they originally did, though they are 3D in Yoshi's Island (they turn 2D when rotating).

Mario Sports Superstars
The dummies that appear in the Ring Challenge mode of the soccer sport in Mario Sports Superstars are made of Rotating Blocks, flipping over when they are struck by the ball.

The Super Mario Bros. Movie
A poster for The Super Mario Bros. Movie of Mario on the obstacle course features some Rotating Blocks in the background.

Other appearances
The blocks from Super Mario RPG: Legend of the Seven Stars, Bike Pads from Mario & Luigi: Superstar Saga, and yellow blocks from Paper Mario resemble Rotating Blocks.

Although actual Rotating Blocks do not appear in Mini Mario & Friends: amiibo Challenge, there are blocks that have an identical design, primarily found in Mini Luigi's world, Moonlight Mansion. They initially appear as transparent Brown Blocks from Super Mario World, referred to as invisible blocks, but they turn solid and yellow when a nearby candle is lit, allowing the Minis to walk on them.