Reapling

Reaplings appear in Phantom Hourglass, when Link makes his way on to the Ghost Ship. Much like Phantoms, Reaplings have the ability to incapacitate Link, which causes him to start the level of the dungeon over.

Reaplings can be avoided by only moving when they have their backs are to Link. Unlike Phantoms, Reaplings can move and see through walls. They are immune to most forms of attack and cannot be killed, but a shot to the back with an arrow will temporarily stun them.

They seem to be subservient to the Diabolical Cubus Sisters, since the Sisters initially tried to leave the task of dispatching Link to them, and were later disappointed when they failed.