Thwomps are floating rock-like enemies in the Mario Series. Thier way of attacking is smashing things beneath them. They fall down from the ceiling or the sky and try to crush anyone who goes under them or near them. A subspecies of Thwomps called Grindels move horizontally and they first appeared in Super Mario Bros. 3. Thwomps can be defeated with a Star, or Mario can throw Hammers at them as Hammer Mario. Most Thwomps appear in castles and fortresses but sometimes the can be found in deserts and underground areas. Some say that Thwomps are born in the Thwomp Volcano. Due to their rock-like nature, they are often categorized along with Chain Chomps and Bob-Ombs.
In Super Mario 3D World Thwomps appear in many levels. The can be found in Bowser's levels, Thwomp Desert and Piranha Sewers. Other species like Whomps and Wallops appear. Tail Thwomps are also introduced but they are very rare.