The draugr or draug (Old Norse: draugr, plural draugar; modern Icelandic: draugur, Faroese: dreygur and Danish, Swedish and Norwegian: draugen), also called aptrganga or aptrgangr, literally "again-walker" (Icelandic: afturganga) is an undead creature from Norse mythology.
The word draugr can be traced to a Proto-Indo European stem *dʰrowgʰos "phantom", from *dʰrewgʰ- "deceive". The Old Norse meaning of the word is a revenant.
The will appears to be strong, strong enough to draw the hugr [animate will] back to one's body. These reanimated individuals were known as draugar. However, though the dead might live again, they could also die again. Draugar die a "second death" as Chester Gould calls it, when their bodies decay, are burned, dismembered or otherwise destroyed.
Draugar live in their graves, often guarding treasure buried with them in their burial mound. They are animated corpses — unlike ghosts they have a corporeal body with similar physical abilities as in life. Older literature makes clear distinctions between sea-draugar and land-draugar.
Draugar possess superhuman strength, can increase their size at will, and carry the unmistakable stench of decay. "The appearance of a draugr was that of a dead body: swollen, blackened and generally hideous to look at." They are undead figures from Norse and Icelandic mythology that appear to retain some semblance of intelligence. They exist either to guard their treasure, wreak havoc on living beings, or torment those who had wronged them in life. The draugr's ability to increase its size also increased its weight, and the body of the draugr was described as being extremely heavy. Thorolf of Eyrbyggja saga was "uncorrupted, and with an ugly look about him... swollen to the size of an ox," and his body was so heavy that it could not be raised without levers. They are also noted for the ability to rise from the grave as wisps of smoke and "swim" through solid rock, which would be useful as a means of exiting their graves.