Crush Traps, patterned after the Thwomps of the Super Mario Bros. franchise, appear in the Temple. If you come within range of one, it'll slide in your direction, stopping only when it hits a solid obstruction like a wall. Touching a smash trap is worth 10 damage for very brief touches or instant death in some cases, much like a boulder. It's possible to briefly stand on top of one with no damage taken, though, provided it's not moving upward.
Unlike most traps, which can be triggered by enemies and thrown objects, crush traps are only triggered by the presence of your character.
Interestingly, Crush traps will, befitting of their name, break through falling platforms. As these two objects appear in different areas, this is a feature exclusive to custom levels and the Sun Room.
Crush traps will also kill any enemy caught in their path, but do not cause damage to the Mummy.