A shaman gains the power of a skinwalker, or yee naaldlooshii in the Navajo language, by renouncing the traditional ways of Navajo magic and adopting the teachings of the Witchery Way. At the highest level of priesthood, he or she must then make the final sacrifice of murdering a blood relative: a parent, a sibling, or a child. With this destruction of their humanity, they have gained the evil power inherent to the yee naaldlooshii.
A skinwalker can take the form, speed and strength of any animal it wishes, depending on what abilities it needs. Many Navajo believe it can even steal the skin, or body, of a human being; locking eyes with a skinwalker allows it to immerse itself into your body.
Some say skinwalkers are easy to recognize in animal form, as they are unable to move entirely naturally, and some Navajo describe them as distorted and mutated forms of the animals they are emulating. Furthermore, a skinwalker’s eyes glow like an animal’s when in human form and appear human when in the form of an animal.
Many Navajo can tell stories of encounters with skinwalkers. They will sometimes try to break inside homes to attack the residents, and will often bang on the walls, climb onto the roofs and peer inside through windows in strange, animal-like forms. Skinwalkers are also known to attack cars and cause accidents. And that's not all; the yee naaldlooshii are also believed to be graverobbers and necrophiliacs.
The yee naaldlooshii can use magic to curse people and cause suffering and death. They use a mixture called corpse powder which they blow into their victim’s face. Soon after, the victim’s tongue turns black, they go into convulsions, and eventually die. They can also use spit, hair and old clothes to send a curse at a particular person. Because of this, many Navajo never spit and make sure to destroy any hair or nail clippings.
Skinwalkers are agile and fast enough to easily keep up with a speeding car. Some believe they can read thoughts and make any animal or human noise they want, using tricks like the cry of an infant to lure victims out of the safety of their homes.
Killing a skinwalker is very difficult due to their great power. Often people attempting to shoot one find their guns jammed, and if the rounds do fire, they have no effect. While the Navajo have magical protections against the yee naaldlooshii, there is only one certain way to defeat them: if you see a skinwalker and call it by its true name, it will die.
Skinwalker lore is no mere children’s tales to the Navajo people. The subject is not open to discussion, even today, and the Navajo are reluctant to talk about it to outsiders. After all, a stranger asking questions about skinwalkers just might be one himself.