Draugr

Draugr is a word for a dead person who walks again. Grettis saga applies it to Kárr the Old, and modern scholars use it for other saga revenants, such as Glam in Grettis saga and Thorolf in Eyrbyggja saga.

In Grettis saga, in the 1869 translation by Eiríkr Magnússon and William Morris, the ghost Glam will not stay at rest. People who saw him fainted, and some went out of their minds. Soon after Yule men believed they saw him at the farm, and many fled on the spot. He then took to riding on the roofs at night until they nearly caved in, and walked about by day as well, so that men barely dared to go up into the dale.

Eyrbyggja saga, in the 1892 translation by Morris and Magnússon, tells of Thorolf. As the summer went on, people saw that he did not rest, and nobody was safe outdoors after sunset. The oxen once yoked to Thorolf became troll-ridden, cattle that came near his burial mound went mad and bellowed until they died, and the herdsman at Hvamm was often chased home by him. A later chapter, which the translators head A door-doom at Frodis-water, ends the hauntings at that farm. Kiartan and his people come in, and the priest carries holy water and holy things through the house. The next day they sing the hours and a mass, the walking stops, and Thurid recovers from her illness.

The word itself is a scholars' label as much as a saga one. Wikipedia notes that in Grettis saga Kárr the Old is called a draugr outright, while Glámr (Glam in the translation) is never called one in the text, though the saga does call him a troll. Modern scholars still class him as a draugr. Beings the sagas call only revenants (aptrgǫngur) or hauntings are also commonly discussed as draugar. The Reykjavík Grapevine's comic 2015 recap of Eyrbyggja saga calls Thorolf a draugur or afturganga, glosses the second word literally as again-walker, and stresses that he haunts in a solid, reanimated body.