The Meaning of Dragon in Old Norse‏

[Dept of PMM Artists & things]

A draugr or draug (original Old Norse plural draugar, as used here, not draugrs), or draugen (Nor., Swe. and Dan., meaning "the draug"),
also known as aptrgangr (lit. "after-goer," or "one who walks after
death") is an undead creature from Norse mythology. The original Norse
meaning of the word is ghost, and in older literature one will find
clear distinctions between sea-draug and land-draug. Draugar were
believed to live in the graves of dead Vikings, being the body of the
dead. Views differ on whether the personality and soul of the dead
person lingers in the draugr. As the graves of important men often
contained a good amount of wealth, the draugr jealously guards his
treasures, even after death.

The Walking Dead: Draugr and Aptrgangr in Old Norse Literature

For the Vikings, the concept of the afterlife was often much more immediate than glorious skaldic tales of Valholl or the Christian's
Heaven: once the dead body was placed within the grave, it was believed
to become "animated with a strange life and power" (Hilda
Ellis-Davidson. The Road to Hel. Westport CT, Greenwood P., 1943. p.
96). The dead person continued a sort of pseudo-life within the grave,
not as a spirit or ghost, but as an actual undead corpse similar in
many respects to the nosferatu or central European vampire
(Ellis-Davidson, Road to Hel, p. 92).

The undead were known by various names. The haugbui (from haugr meaning "howe" or "barrow") was a mound-dweller, the dead body living
on within its tomb. The haugbui was rarely found far from its burial
place, and is the type of undead usually found in Norwegian saga
material. The draugr was "the animated corpse that comes forth from its
grave mound, or shows restlessness on the road to burial"
(Ellis-Davidson, Road to Hel, p. 80). Also known as aptrgangr (lit.
"after-goer," or "one who walks after death") the draugr is the roaming
undead most frequently encountered in the Icelandic sagas. Whichever
name is used, the undead of Scandinavia was a physical body, the actual
corpse of the deceased, and though the term "ghost" may be used to
describe it, modern connotations of a phantom or incorporeal spirit do
not apply to these supernatural creatures. From here, the monster
Grendel, with its "horrible fierce eyes" and blood lust, seems to
derive in part from some folk belief that perhaps sprouted from the
vampire story. It may even be that when the Beowulf poet refers to
Grendel's mother as a "she-wolf," he is depending on his audience's
understanding of lycanthropy.