Flomp

Floating Plates are a type of Thwomp appearing in the game Super Mario Galaxy 2. They appear as a green platform with spikes on their sides and have a similar face to a Sliding Stone. They move from side to side. At first glance, they seem like ordinary platforms, but after a few seconds, they make a malicious face and quickly flip over. If Mario or Luigi is on one of these platforms when they flip, he will be knocked high into the air. They appear in only two galaxies: Bowser's Lava Lair and the Grandmaster Galaxy.

Trivia

 * Floating Plate's facial expressions look similar to Tox Boxes