Nightmares are creatures that appear as shadow-like creatures, though there seems to be two kinds of Nightmares. Some Nightmares seem to come from The Mists. On the other hand, there are Nightmares which seem to be hostile spirits, such as the ones encountered during the quest Haunted and the Vaettirs such as Nulfastu Earthbound, a fallen nature spirit that entraps other spirits (that take the shape of Vaettirs).
 List of hostile NPCs
- Only encountered in The Aurios Mines.
- Only encountered in quests.
- The affiliations outside of parentheses are by mechanics, those found inside of parentheses are by lore.