Mattermouth

Mattermouths are enemies found in the game Super Mario Galaxy 2 that resemble dinosaur skulls (or are possibly Dry Bones skulls). They are found in galaxies such as Haunty Halls Galaxy and will eat away part of the floor, which will regenerate after a few seconds. Mario cannot destroy it, but can stop it for a little bit by stomping it's head. If Mario is attacked by one of these enemies he will lose a wedge of his health.