In Navajo tradition, a skin-walker is a person who can shapeshift into an animal. These people, called yee naaldlooshii in the Navajo tongue, are human and part of the tribe during the day, but they perform evil deeds in animal form at night.
According to tradition, the skin-walker has subverted a tribal taboo to gain his power, usually murdering a family member but sometimes killing another innocent or committing incest. Skin-walkers can assume the shape of any animal but are most likely to choose the shape of coyotes, wolves, foxes, eagles or owls. They may also steal the face of someone else. Navajos believe that if a person meets the eyes of a skin-walker, he will freeze in terror, giving the skin-walker more power.