Thwimps are recurring enemies in the Legend of Zelda series. They are essentially smaller versions of Thwomps, the only difference being that they drop more quickly from ceilings. They are encountered only inside dungeons, namely the subterranean areas that use side-scrolling 2-D maps. Thwimps originated as enemies in the Super Mario Bros. series.
Thwimps are found exclusively in dungeons. They are usually found in groups and can be evaded by simply walking below them without stopping.
The name "Thwimp" appears to be a portmanteau of "Thwomp", their parent enemies, and the derogatory term "wimp," likely referring to their small size and/or the little threat they present.