Draugr

Draugr are unresting undead which often appear in Icelandic sagas. These kinds of undead still roam their burial mounds and in some stories, they even are able to leave them. Their appearance varies depending on the cause of their death. It is also told, they possess magical or supernatural powers which makes it possible for them to change into animals and to predict the future. With the right spell, they also can become helpful. In the old stories, they can be killed by chopping off their head and to burn them. Normal weapons often were useless. Some discovered runestones have grave-binding inscriptions.

Glámr is a powerful draugr who appears in the "Grettis Saga", in which Grettir kills the undead, but then is cursed by it.

Source
The draugr originate from Norse mythology.

Media
Draugr appear in the following media:

Games

 * God of War
 * God of War
 * God of War
 * God of War

Novels

 * Eyrbyggja Saga
 * Grettis Saga
 * Njáls Saga
 * Peer Gynt by Henrik Ibsen