A Naagloshii or Skinwalker[Footnote 1] is an immortal semidivine being with the ability to change shape. Harry Dresden has had personal dealings with both Shagnasty and Goodman Grey. It is first mentioned in Turn Coat.
Naagloshii are identified as the messengers of the Navajo[Footnote 2] Holy Ones. They are semidivine beings which can morph into the general shape of any animal. Instead of being an exact copy of a gorilla, for example, it will be gorilla shaped (longer arms than legs, tremendous strength, etc.) but still recognizably a demon. The term skinwalker is actually a more general term for naagloshii and those who were taught magic by them.(reference needed)
The skinwalker was virtually its own ley line, its own well of power. It had so much metaphysical mass that the dark river of energy flowing up from beneath the tower was partially disrupted by its presence, in much the same way as the moon causes tidal shifts. The island reflected that disruption in many subtle ways. Animals fled from the naagloshii as they might from the scent of a forest fire. Insects fell silent. Even the trees themselves seemed to grow hushed and quiet, despite the cold wind that should have been causing their branches to creak, their leaves to whisper.— DresdenNaagloshii are shapeshifters. They are capable sorcerers that can use their own natural abilities. The more afraid you are, the more powerful they become. They have a horrific psychic stench and when seen with a wizard's sight can be devastating and debilitating. Although as far as we know that may be due to the Skinwalker in question being old and evil. Its difficult to say what kind of thing Dresden would see if he were to use his sight on Goodman Grey for instance.
Naagloshii get stronger by eating the essence of practitioners—they eat magic and add their victim's power to their own. Eating a wizard gives the naagloshii considerable power; therefore, a wizard's power attracts naagloshii, especially if the wizard is wounded. However, the longer the naagloshii stay away from their home tribal lands, the more power they lose.
Only a true shaman of the blood can drive naagloshii away by performing a Navajo Enemy Ghost Way sing.
True skinwalkers are millennia old. They are typically only found in the American Southwest on tribal lands; it costs them power to stay away too long. The Ute, the Navajo, and other Southwestern native tribes have their own stories about them.
The English word for semidivine doesn't really cover it. Most skinwalkers are just people—powerful, dangerous people. They're successors to the traditions and skills taught to avaricious mortals by the originals—the Naagloshii. Shagnasty is a real Naagloshii. Per some Navajo stories, the Naagloshii were originally messengers for the Holy People when they were first teaching humans the Blessing Way. Although they were supposed to leave the mortal world with the Holy People, a few didn't. Their selfishness corrupted the power the Holy People gave them. It can be assumed this happened pre-history, several millennia ago.
Donald Morgan informs Harry Dresden of a previous encounter with a skinwalker, when Morgan led it onto a nuclear test range and stepped into the Nevernever, leaving the skinwalker to be destroyed by a nuclear weapon.
In the seriesEdit
In Turn Coat, Harry Dresden first encounters the Naagloshii, with Shagnasty being one of the main villains. In Dresden's first encounter he views it with his Sight and sees something so horrible it leaves him incapacitated for the next several hours and with flashbacks for years after. Dresden describes it as something rotten and horrible, surrounded by a haze of absolute wrongness.
Throughout the book Shagnasty is an almost unstoppable force, assaulting the Raith Estate and besting Dresden easily. But Listens-to-Wind is able to drive it away with an impressive display of entropy magic and shapeshifting. Listens-to-Wind states that its possible, but not certain, that he could have defeated it, and that Shagnasty fled because he could not easily win, displaying a level of calculated caution.
In Ghost Story, Uriel states that the Naagloshii have a need to show that every being they encounter is as flawed and prone to darkness as they are. He also says that this gives them a sense of false peace.
First introduced in the television series of The Dresden Files in the first episode, "Birds of a Feather", it can kill its victims and using its ability, skin them. Then it can take the form of the person. In the TV series it was destroyed with a magical energy amplifying and exploding device nicknamed the Doom Box.