Acheri or Anchheri is mountain ghost in form of young female child in belief of Kumaoni people of Kumaon and Garhwal regions in Uttarakhand state in Northern India. They live high in the hills and sometimes, at night, they descend to lower altitudes to play near the shores of lakes and in flowering meadows. They appear in groups, cavorting and chasing each other in what appears to be a frolicsome mood. But if you look closely you will see that their eyes are hollow and sunken, for these are the ghosts of girls who died unnatural deaths — either from murder, disease, or neglect.

Despite their playfulness, they are very dangerous. If a living girl sees them and tries to join their games, she will die. It is unsafe to visit the favoured playgrounds of Anchheri even during the daytime after they have left. When little girls or elderly people fall sick, it is thought to be because the shadow of an Anchheri has fallen on them.

Anchheri hate the colour red. Some say that the best defense against them is to tie a red ribbon around one’s neck. But according to other stories, the colour makes the Anchheri fly into a rage, so red clothing may invite an attack rather than repel it.

These ghosts appreciate gifts — especially jewellery, kajal for the eyes, and colourful saris or shawls. If they are regularly propitiated with such things, they cause less trouble for the living.

Anchheri play a role in a famous Garhwali folk ballad known as Jeetu Bagdwal. This is the tragic tale of a young man named Jeetu, said to have lived around 500 years ago during the reign of Raja Man Singh:

Jeetu had to make a journey to his sister’s village to invite her for a pooja. It was a long journey, and after travelling some distance, Jeetu stopped to rest and play his flute.

The Anchheris who lived on the nearby mountain of Khait Parvat heard his music. They floated down through the trees and started to dance around him in a circle. The sound of the bells on their anklets hypnotized Jeetu, and he slowly fell asleep. Then the ghosts entered his body through his eyes, his ears, and his hands, and began to drink his blood.

Shaking himself awake, he insisted that the spirits let him go so that he could meet his sister. He promised that once he had returned and the pooja was done, they could take him. The Anchheri agreed.

Jeetu finished the journey to his sister’s village, brought her back home, and conducted the rest of the pooja successfully. But as soon as the rituals were over, the Anchheri swept down from the hills and stole him away; and as they left, they caused a calamitous landslide which killed his sister and every other member of his family (1533: p.35-36).

It was introduced for European readers by first commissioner of Kumaon region G.W.Traill in his Statistical Sketch of Kumaon first published in 1828:

Acheri, or fairy, the ghosts of young of female children; these reside on the tops of the mountains, but descend at dusk to hold their revels in more convenient spots. To fall in with the train, at the time. is fatal, as the Acheri punish such intrusions with death: they occasionally also molest those who may cross the sites of their abodes during the day, more particularly females, who may have any red particles of dress on their person at the time, the Acheri bearing a peculiar antipathy to that color. When female children are taken suddenly ill, it is immediately concluded that the Acheri have cast their spell or shadow (chaya) on the child, with the view of adding her ghost to their numbers. The optical illusions and shadows, seen in various mountainous countries, are also occasionally visible on some of the mountains in this province, which are accordingly celebrated as the peculiar resort of the Acheri, as the processions of elephants, horses, &c., which sometimes appear on the summits, are naturally ascribed to those ideal beings. A hill opposite to Srinagar, is celebrated in this respect; the train of shadows which. from time to time, appears to move along its ridge, continues visible for some minutes, and is, in consequence, viewed by numbers of inhabitants of the town. It therefore certain, that these shadows originate in physical causes, and are not created by the imagination of individuals. The theory, by which this illusion is explained in other places, is particularly applicable here, as the shadows in question, are invariably seen at the same hour, that is, when the sun is sinking below the horizon.

Traill G.W. "Statistical Sketch of Kumaon" (1199: p.66)

For more than a century and a half Acheri remained character of folklore of India and since then wasn't many additions to that story of Traill. In novel Dead Storm by Richar Seib Acheri is demonic female creatures "in a sense dead but not dead" and subdued to more powerful male demons by the name of Baykak in Odjibwe folklore (1202: p.199). It is possible that this novel became the source of confusion as different books since then describe Acheri legend in its original Indian form as part of folklore both Indian and of Ojibwe's. Some exploited this idea even more like Corker Johnston in his docu-fiction book "Acheri Demon Haunting" (1201). The "intriguing" fact that such different people had the similar legend according to Johnston was due to the fact that both had paleocontact with race he calls "Ancient Aliens" (1201).

The Mythology of Supernatural by Nathan Brown claims that Acheri legend is of Native American origin and has nothing to do with Hindu folklore bringing no authentic evidence to support this. Red color on clothing became protection from Acheri from being endangering color in Traill's report.

In episode All Hell Breaks Loose: Part One (2.21) of Supernatural series Acheri appeared as demon able to manifest itself in a form of a little girl without possessing human body.