|In Native American and Norse legend, a skin-walker is a person with the supernatural ability to turn into any animal he or she desires. The Mohawk Indian word "limikkin" is sometimes used to describe all skin-walkers. It is also known as the Yenaldooshi. Possibly the best documented skinwalker beliefs are those relating to the Navajo Yeenaaldlooshii (literally "with it, he goes on all fours" in the Navajo language). A Yeenaaldlooshii is one of several varieties of Navajo witch (specifically a practitioner of the Witchery Way, as opposed to a user of curse-objects or a practitioner of Frenzy Way). Technically, the term refers to an ánt’hnii who is using his (rarely her) powers to travel in animal form. In some versions men or women who have attained the highest level of priesthood then commit the act of killing an immediate member of their family, and then have thus gained the evil powers that are associated with skinwalkers.
The ánt’hnii are human beings who have gained supernatural power by breaking a cultural taboo. Specifically, a person is said to gain the power to become a Yeenaaldlooshii upon initiation into the Witchery Way. Both men and women can become ánt’hnii and therefore possibly skinwalkers, but men are far more numerous. It is generally thought that only childless women can become witches.
Although it is most frequently seen as a coyote, wolf, owl, fox, or crow, the Yeenaaldlooshii is said to have the power to assume the form of any animal they choose, depending on what kind of abilities they need. Witches use the form for expedient travel, especially to the Navajo equivalent of the 'Black Mass', a perverted sing (and the central rite of the Witchery Way) used to curse instead of to heal. They also may transform to escape from pursuers.
Some Navajo also believe that skinwalkers have the ability to steal the "skin" or body of a person. The Navajo believe that if you lock eyes with a skinwalker they can absorb themselves into your body. It is also said that skinwalkers avoid the light and that their eyes glow like an animal's when in human form and when in animal form their eyes do not glow as an animal's would.
A skinwalker is usually described as naked, except for a coyote skin, or wolf skin. Some Navajos describe them as a mutated version of the animal in question. The skin may just be a mask, like those which are the only garment worn in the witches' sing.
Because animal skins are used primarily by skinwalkers, the pelt of animals such as bears, coyotes, wolves, and cougars are strictly tabooed. Sheepskin and buckskin are probably two of the few hides used by Navajos, the latter is used only for ceremonial purposes.
Often, Navajos tell of their encounter with a skinwalker, though there may be some hesitancy to reveal the story to non-Navajos, or (understandably) to talk of such frightening things at night. Sometimes the skinwalker will try to break into the house and attack the people inside, and will often bang on the walls of the house, knock on the windows, and climb onto the roofs. Sometimes, a strange, animal-like figure is seen standing outside the window, peering in. Other times, a skinwalker may attack a vehicle and cause a car accident. The skinwalkers are described as being fast, agile, and impossible to catch. Though some attempts have been made to shoot or kill one, they are not usually successful. Sometimes a skinwalker will be tracked down, only to lead to the house of someone known to the tracker. As in European werewolf lore, sometimes a wounded skinwalker will escape, only to have someone turn up later with a similar wound which reveals them to be the witch. It is said that if a Navajo was to know the person behind the skinwalker they had to pronounce the full name. And about three days later that person would either get sick or die for the wrong that they have committed.
According to Navajo legend, skinwalkers can have the power to read human thoughts. They also possess the ability to make any human or animal noise they choose. A skinwalker may use the voice of a relative or the cry of an infant to lure victims out of the safety of their homes.
The legend of the skinwalker tell of god giving the people a gift of transformation and was used only against their enemies. Over time, the people began to abuse this power, thus bringing god to earth to reclaim it. Some gave the power up and others hid with it and passed the knowledge to others.
Some tribes believe that skinwalkers can use the spit, hair, or shoes and old clothing of a person to make curses that will attack that specific person. For this reason many Navajo will never spit or leave shoes outside. They also take great care to see that any hair or nail clippings are burned. Urine cannot endanger a person because it is considered too acidic.
In ancient Hopi culture there was a ritual ceremony once performed called the Ya Ya Ceremony. In this ceremony members would change themselves into various animals using the hide from the animal they chose, and the members use certain animal attributes like sight, strength,etc. The ceremony was banned after members developed a disease of the eyes.
In Norse folklore, a skin-walker is a person who can travel in the shape of an animal and learn secrets, or take on certain characteristics of an animal. The person is then said to be wearing that animal's hide. The most well-known example of the latter is the warrior who takes on the strength and stamina of a bear, called "bear shirt" or ber sarkur, the origins of the word berserker; similarly, there were wolf-based warriors, called ulfheðnar or "wolf-coats". They were said, aside from the battle-rage the animal spirit granted, to have the ability to send out their soul in the form of their animal, in a practice called hamfarir or "shape-journey".
According to Mythology, the Norse hero Sigmund and his son Sinfiolti became Skinwalkers for a short time, discovering two magic wolf skins that turned them into wolves when they put them on. When they became overcome by their animal instincts and began fighting over meat, Sigmund almost killed his son and so they decided to burn the skins.
The use of an animal shape for other purposes was considered unholy, and people accused of having such abilities were frequently cast out or summarily executed. Females so charged got off more lightly.
Though it was never referred to as a skinwalker, only a shapeshifter, the boys came up against one in St. Louis, Missouri and then in Milwaukee, Wisconsin. In their case, shapeshifters/skinwalkers kill people and assume their shapes. The only thing that could hurt them was silver and they could be killed by a silver stake to the heart, though Dean used a silver letter-opener.
The same went for a werewolf in San Francisco, California: they were only hurt by silver. The werewolf was a young woman, who had no idea she was turning and murdering people, then ripping their hearts out of their chest. After hunting down the werewolf that turned her and killing it with a silver bullet to the heart to try to get her to revert back to normal and realizing it didn't work, the boys were forced to kill her. This was arguably the most dramatic scene on Supernatural, when Madison asks Sam to kill her.