These spirit-animated corpses of the dead not only preyed upon careless travellers but also appeared to be undead beings that defied nature and the very rule of Ilúvatar (although the true souls of the deceased had indeed passed into the West). It was very difficult to determine how they were made, but perhaps many of them were Númenórean victims of cursed blades used on them in battle, which may explain Merry's nightmare and the "spear in his heart".
Barrow-wights appeared as dark, shadowy forms with glowing lights for eyes. They attempted to capture living beings and sacrifice them to whatever evil power they now worshiped (in Middle-earth, usually Morgoth), thus gaining the life energy of the victims, which is what wights "fed" on. As they drew energy, they became more corporeal, showing hands like claws and faces like skulls. If seen with magical means, they appeared as faded, pale versions of their former living selves. They possessed a Fear aura that was an intrinsic facet of their being; in addition, they could either paralyze or use sorcerous sleep on their victims to keep them immobile while the wights drained their life force. When all of the victim's constitution was gone, he died. Barrow-wights could use the actual weapons and magical items buried with them.
- Retrieved from Realms of Arda; original reference: [ICE MERP 2016]