The tooth fairy is a fantasy figure of early childhood. The folklore states that when children lose one of their baby teeth, they should place it underneath their pillow and the tooth fairy will visit while they sleep, replacing the lost tooth with a small payment. The tradition of leaving a tooth under a pillow for the tooth fairy to collect is practiced in various countries in the Anglosphere.
The small, imp-like fairy has long, slender arms, developed for reaching under the child's pillow and retrieving the tooth. What exactly they do with the teeth is up for speculation, but it is important to note that if you encounter a tooth fairy, do not attempt to interfere with it. They can become quite hostile if their tooth gathering compulsion is interrupted.