Bomp

Pushy Walls are a sub-species of Thwomp that first appeared in Super Mario 64. They are living, pushing, protruding stones that act as obstacles in many games.

Super Mario 64
At the beginning of Whomp's Fortress, they go through a pattern of pushing, trying to shove Mario off a cliff, and to his death. They also appear in many levels including Lethal Lava Land. The beginning and end Pushy Wall in Whomp's Fortress are thinner than the center Pushy Wall. Their eyes have a blue outline with blue pupils. The eyes are also looking like peeling out, thanks to the thick outline on the eyes.

Super Mario 64 DS
In Super Mario 64 DS, the eyes were removed on the Pushy Walls, to surprise new players. To avoid a Pushy Wall, Mario can jump on them, or wait until he can pass.

Super Mario Galaxy
Pushy Walls also appear in Super Mario Galaxy, but with a different, more Thwomp-like look and face. They first appeared in Buoy Base Galaxy.

Super Mario Galaxy 2
In Super Mario Galaxy 2, they appear with the same role and appearance as in Super Mario Galaxy. They appear in the Fluffy Bluff Galaxy and the Throwback Galaxy, which is a remake of Whomp's Fortress.