The Sluagh are a class of malevolent spirit in Irish and Scottish folklore, believed to be the restless souls of individuals barred from all three afterlives (Heaven, Hell and the Otherworld) - thus these spirits would gather like a flock of birds and prey upon the living, always arriving from the West.

Seen as troublesome and destructive the Sluagh would try and steal the dying souls of innocents to add to their mass, thus in days of old windows facing West were often closed to try and prevent the spirits abducting the souls of those on their deathbed.

The Sluagh are thus also made up of tormented souls of the innocent who have been dragged away by the restless dead to share in their eternal torment, a fate that would doubtlessly strike dread into the hearts of those who believed in such things back in the superstitious past.

The Sluagh are not to be confused with the similiar concept of the Unseelie Court, however they share similarities with the Wild Hunt.