Schemes of the Lich King
Tooth Fairies are evil, malignant beings with a desire to forcibly remove teeth from their victims for no other reason than some kind of sadistic pleasure. They are born out of spite and hatred and are likely corrupted fey or are spawned with evil magic runs amok.
Each night, gangs of tooth fairies stalk humanoid settlements, using their magic to confuse and distract their victims, and reveling in the looks of horror on their victims’ faces as the fey suddenly appear out of the darkness with their dirty, bloody pliers. The fairies then lull their targets to sleep and get to work at claiming their prizes. Some cautious fairies bite their targets to paralyze them and ensure the victims can’t wriggle away from the fairy’s grasping pliers; others enjoy the sounds of creatures awakening to their own screams as the fairy torments them with harsh pinches and painful tugs on fingers, teeth, or eyelids.
Tooth fairies use stolen teeth either to replace their own lost teeth (if the stolen teeth are small) or to decorate their dwellings, which usually lie inside abandoned buildings or knotholes in trees. Used as stools, carved into minuscule sculptures, or worn as crowns, the prized teeth serves as trophies of their successful raids.