Shapeshifters as Skinwalkers is primarily a Navajo belief, (some Hopi and Yaqui). It is said that the first skinwalkers came about from the time of the "Long Walk", when tribes were forcibly removed from their lands for European expansion. There were some who used this as a means of escaping the soldiers, and getting revenge.
The Navajo name for skinwalker is Yee Naaldlooshii. Its literal meaning is "With it, he goes on all fours here and there". They are able to transform by a perverted ceremony and song called "Witchery Way", using powers to travel in animal form. Animals used can be coyote, wolf, fox, owl and crow. But some say, even bear or cougar, the pelts of these animals are strictly taboo for keeping or using.
It is said that if you should ever lock eyes with a skinwalker, it can absorb itself into your body. This is one of the reasons most Navajos will not look directly at a person's eyes. Though Europeans found this shifty and sly, thinking all indians guilty of evil thoughts, it was and still is a long tradition of keeping oneself safe from witches.
When a skinwalker targets you, it comes at night. Sometimes banging on walls, knocking on windows, or climbing on the roof. They also might shoot you with a bone bead or shard from a blow gun, or drop burned bone ashes down the chimney. If it enters your body, you will wither away and die. They are said to be fast, agile, and impossible to catch.
Many years ago, I taught high school for a couple of years at a Navajo Reservation school. The tribe provided trailers for their teachers and families to live in. When I was ready to move into my trailer, my brother searched it thoroughly first, even down to the pipes underneath. When I asked him why, he told me some people thought there was a witch or skinwalker around that might harm me or my family.
At that time I was unfamiliar with what he meant, so asked him to explain better. He said one of the teacher families had had a baby while there, but the baby had died. Upon searching the trailer, they found a small effigy tied to the pipes underneath the trailer, wrapped in a piece of the baby's blanket, with bone beads and dust!
Well that was pretty creepy to me, but I wasn't sure I believed it, especially since my brother can be quite the teaser. I was soon reassured that it was a true fact.
One night, after living there for about 6 or 7 months, I heard a lot of weird noises outside. I had locked all my doors and windows and pulled all the shades, but of course I was curious, with all the dogs barking and howling.
When I looked outside (through the window, NOT the door), I actually SAW, with my own two eyes, a nude man climbing onto the roof of a trailer across the way from me! I say nude, but he actually had on moccasins and was wearing an animal skin, hanging off his shoulders, with the head where his should be! He started reaching into a bag he had and moving his arm while stepping in a certain pattern over the roof, almost like a dance. All of a sudden, it seemed as though he could tell I was looking, because his head snapped around directly toward my trailer!
OMG! I was sooo freaked out, that I reached and turned my porchlight on quickly, hoping he really couldn't see me. At that, he made a horrible sound, between a scream and a howl, and literally LEAPT off the roof of the trailer and ran.
I would like to know how he could leap from the top of a trailer and hit the ground running, if he didn't have *something* sort of working for him. There are a lot of hallucinogens that grow wild in the deserts. So I have thought maybe drugs could let them do those sort of things, and also that perhaps they only *think* they become that animal instead of actually doing it.
At any rate, having seen it myself, I can truly say they ARE real, and yes, they are scary as heck! Brrrr!