There’s loads of stuff on the Draugr in the sagas, particularly the Icelandic ones.
Hilda Ellis-Davidson did a bunch of work in her “The Road to Hel” (Westport, CT, Greenwood Press 1943) as well.
The Draugr are actually considered to be less like what is a normal conception of a ghost and more like animated corpses of immense physical strength and often shapeshifting ability. In short, Nordic Undead.
There are several kinds. The haugbui are more common in Norwegian Myth and are pretty much home bodies, rarely found far from their burial place and don’t threaten anyone that’s not actually hanging out on their burial mound….kind of like a wight that way.
Draugr are more common in Icelandic myth and roam around. Another name for these guys is Aptrgagnger (lit: ‘after goer’)
Whatever they’re called they differ from ghosts in that they have a physical presence, usually huge and sometimes partially rotted.
There’s also tales that speak of these walking corpses having knowledge of the future and other magical abilities, such as ‘swimming’ through solid stone.
The over all feeling in the sagas about the Draugr is an overwhelming resentment and jealousy of the living, leading to physical and magical attacks.
They are also portrayed as having insatiable hunger, perhaps a reflection of their desire for life.
Commit & Conquer
“Chance favors the prepared mind.”
Louis Pasteur