Grindel

Grindels are enemies encountered only in the pyramid sub-area of Shifting Sand Land. They are large, cubic enemies wrapped in bandages or cloths, with two bluish eyes, large, dark eyebrows, and an unwavering grin for which they are named. They are similar in behavior to Thwomps, in that they levitate upwards before crashing back down, crushing anything below them. However, some move forwards and backwards along a track while "jumping" up and down, akin to the Mr. Blizzard enemy encountered on the bridge in Cool, Cool Mountain.

Much like Thwomps, they can be jumped on top of and used as platforms by Mario.

There is a variant of the Grindel called the Spindel, which has wildly different behavior.

Waiting Grindel
Much like Thwomps in their 2D appearances, Grindels have been reported to have a different behavior in personalized copies. Instead of moving up and down in a rhythm, they remain stationary until the player gets close. When Mario moves under it, the Grindel will attempt to crush him. This gives the player time to react, back up, and safely jump on top of its head.