Draugr take their mythological inspiration and several traits from the draugr, undead creatures from Norse mythology.
It should be noted that one differentiates between sea draugar and land draugar, draugar being plural of draugr:
while land draugar were simply undead with numerous magical abilities, sea draugar were fishermen who had drowned at sea, thus being denied the privilege of being buried.
The mythological draugr can also arguably be considered much more terrifying than the game version, as the land draugar could change their size at will and grow enormous, were somewhat intelligent, possessed superhuman strength, could only be killed if burned completely to ash, and took great pleasure in killing their victims.
Most draugr would crush their victims to death by increasing their size, but other methods included hacking them to bits with their weapons or even eating them alive and drinking their blood.
In Norse mythology Odin was the ruler of draugr and could raise them using a secret, magic song.