They are known as draugar and draugr. They came from Scandinavia they are a form of the living dead of animated corpses that came out of their grave to roam about to cause havoc, trouble, mayhem and panic. They are not similar to zombies they do not have similar features look at my entry on zombies for more info on zombies. The draugr are not mindless, slow but they can develop magical powers. They become like an oracle, possessing information from past, present and future. Some draugr can shapeshift that make them more dangerous as they gain access to people and places that are not normally given to walking decaying corpses. The draugr are not able to rest in peace and it is hostile towards the living and they usually kill their own relatives first. They are not like ghosts when the draugr mission is done they will go back they came from. They are unable to fully die and are angry, resentful and violent. During daybreak, they will return to their graves.
The clue that a corpse has become a draugr is if the body displays restless behaviour during the funeral or on route to the burial site. The people killed by draugr are forced to join them. Their graves give off some light and sometimes supernatural flames.
If someone was a draugr the steps would be taken like the body would be bound to the grave with magical incantation and bindrunes.
The person body big toes are tied together to stop them from walking.
The body is removed from the home to a big area and the area is blocked up. This done so they can still walk around but not escape.
Draugr chase livestock or sometimes ride them. They torment people and torture people especially those walking alone at night. There is lore of knocking on the door at night by the draugr. It’s unknown why they do this as they are strong enough to break the door. Iron amulets are used to protect against draugr. If one does rise is to stake the hearts or behead the draugr with a sword. The corpse cannot be reburied so it must be burned and its ashes thrown to the sea or a secret place far from any people homes. The appearance of a draugr is a decaying body, a stench of death and they are usually more active during the winter season. They are featured The Elder Scrolls V: Skyrim released 2011.
Judika Illes, Encyclopaedia of Spirits the ultimate guide to the magic of fairies, genies, demons, ghosts, gods and goddesses, 2009, Draugr, p 371-72
Go to this youtube video for info on a draugr https://www.youtube.com/watch?v=MGdb0TtfmIM