Thwimp

The Thwimp is a tiny versions of the fabled Thwomp monster which actually first appeared in Super Mario World but later appeared in The Legend of Zelda series with Link's Awakening and the Oracle series. Theses creatures will hug the ceiling and slam down the to ground right before you step under them. It is best to only get close enough for them to fall, and as they make their ascent, run past them. The Pegasus Boots allow you to dash under them as well!