thwomp

Giant stone faces from the Mario series found primarily in the Mushroom Kingdom. They are usually depicted as living stones that are rectangular in shape and encrusted with spikes, and first appeared in Super Mario Bros. 3. They usually try to fall on and flatten whoever is passing under them, but some move horizontally or diagonally as well. It is suggested in Mario & Luigi: Partners in Time that Thwomps may actually have been born out of volcanic activity, and are sometimes described as ghosts.

Their Japanese name is "Dossun".