Skinwalker
In Navajo folklore, 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. In the Navajo language, “yee naaldlooshii” translates to “by means of it, it goes on all fours”. In reality, skinwalkers have one source for their creation, but two ways it is used. Navajo shamans that have fallen to dark arts can call upon forces in the Outer Darkness not unlike a warlock or shadow caster. However, rather than summon an entity or cast a spell, they summon the darkness into their own bodies. Doing so, they merge with the evil spirit and wreak havoc on their enemies. These evil spirits of Warp Magic can change biological material at will, allowing the dark shaman to become twisted animal mockeries. Generally, the skinwalkers will take the forms of wolf creatures that stand on two legs but sprint on all fours, hence their name in Navajo.
The other way that such beings are wrought are through Navajo curses. In these cases, dark shamans curse those they perceive as their enemies. The afflicted then become possessed by the dark spirits and become skinwalkers. However, they are at the mercy of the demon, for they are not Navajo, and as such, the demon will force them to kill members of their own tribe or outsiders. They will slay even their most beloved family members without reservation. An example of this is the skinwalker curse placed on the Ute tribe. If such cursed people are killed or die, the evil spirit inhabiting them will leap into the nearest mortal human and begin anew. This is how the shaman Sani Lightfoot became a skinwalker. However, unlike most victims, he has so far managed to hold the demon in check, using its evil power to try and help the world, humanity, and his tribe.