Thwimp

The Thwimp is a tiny version of the fabled Thwomp monster originally from Super Mario World that later appeared in The Legend of Zelda series with Link's Awakening and the Oracle series. These creatures will cling to the ceiling and slam down to the ground right before Link steps under them. It is best for the young hero to only get close enough for them to fall and run past them as they make their ascent. The Pegasus Boots allow Link to dash under them as well.