In Navajo culture, a skin-walker (Navajo: yee naaldlooshii) is a type of harmful witch who has the ability to turn into, possess, or disguise themselves as an animal. The term is never used for healers.
In the Navajo language, yee naaldlooshii translates to "by means of it, it goes on all fours". While perhaps the most common variety seen in horror fiction by non-Navajo people, the yee naaldlooshii is one of several varieties of, specifically a type of 'ánti'įhnii. The legend of the skin-walkers is not well understood outside of Navajo culture, mostly due to reluctance to discuss the subject with outsiders. Navajo people are reluctant to reveal skin-walker lore to non-Navajos, or to discuss it at all among those they do not trust:
What happens when Rowling pulls this in, is we as Native people are now opened up to a barrage of questions about these beliefs and traditions...but these are not things that need or should be discussed by outsiders. At all. I'm sorry if that seems 'unfair', but that's how our cultures survive. ~ Adrienne Keene
Navajo witches, including skin-walkers, represent the antithesis of Navajo cultural values. While community healers and cultural workers are known as medicine men and women, or by terms in the local, indigenous language, witches are seen as evil, performing twisted ceremonies and manipulating magic in a perversion of the good works medicine people traditionally perform. In order to practice their good works, traditional healers learn about both good and evil magic. Most can handle the responsibility, but some people can become corrupt and choose to become witches.
Animals associated with witchcraft usually include tricksters such as the coyote, but can include other creatures, usually those associated with death or bad omens. They might also possess living animals or people and walk around in their bodies by locking eyes with them. Skin-walkers may be male or female.
Skin-walker stories told among Navajo children may be complete life and death struggles that end in either skin-walker or Navajo killing the other, or partial encounter stories that end in a stalemate. Encounter stories may be composed as Navajo victory stories, with the skin-walkers approaching a hogan and being scared away.
Non-Native interpretations of skin-walker stories typically take the form of partial encounter stories on the road, where the protagonist is temporarily vulnerable, but then escapes from the skin-walker in a way not traditionally seen in Navajo stories that take place away from home. Sometimes Navajo children take European folk stories and substitute skin-walkers for generic killers like The Hook.