A Thorromp in Meloetta's Musical Mess.
Thorromps are fourth dimensional counterparts of Thwomps. They very closely resemble the Thwomps of Super Mario 64. They have appeared in "Into the Fourth Dimension", for the first time in the level, Meloetta's Musical Mess, guarding a D-Star, and then later in Beakstalk Railroad. Their purpose is the fall on people and squash them, pretty much like Thwomps in the Mushroom Kingdom. They serve Dimentio.
They look more realistic than the First Dimesnion Thwomps, and almost look nothing like the new design, for not being blue and not having spines.