Our Wights Are Different

Like Ghouls, gnomes and trolls, "wights" are a kind of supernatural creature whose details no one quite agrees on. Usually evilly affiliated and somehow related to The Undead, but even that is up for debate. Can be an umbrella term for any magical creature, and occasionally a wight is a poorly understood, vaguely undead creature in-universe as well as in its description.

The word comes from a Middle English word meaning literally 'being' (or by extension, 'person'). The modern associations are likely down to Tolkien, whose term 'Barrow-Wight' translates roughly as "Grave-Man", with later adopters presumably missing the significance of the 'Barrow' part.

And no, there is not a Sister Trope called Our Wefts Are Different. Also has nothing to do with the real name of WWE's The Big Show.

Literature

 * J. R. R. Tolkien had "Barrow-Wights", which were described as "a tall dark figure like a shadow against the stars... two eyes, very cold, though lit with a pale light that seemed to come from some remote distance. Then a grip stronger and colder than iron seized him. The icy touch froze his bones and he remembered no more."
 * From associating descriptions, they seem to be evil spirits possessing the corpses of long dead kings in their barrows, and using magic to lead travellers astray.
 * An early draft toyed with the idea of making the Nazgul simply horsed versions of the Barrow-wights.
 * Wights in The Carpet People are a clairvoyant, varnish-mining race who can remember the future; mostly sympathetic, but with something of an Omniscient Morality License attitude. They're really more Our Elves Are Better with Pratchett simply playing with names.
 * In the Books of Pellinor, Maerad destroys "a wight of the abyss". It's implied to be some sort of demon.
 * In A Song of Ice and Fire, the wights are the reanimated corpses of humans, used as undead foot soldiers by the mysterious Others. Also, the Others have been seen using wight horses and other animals as mounts. They are vulnerable only to fire or being chopped into little bits - not even Removing the Head or Destroying the Brain does them in, and contrary to some characters' belief
 * Considering how original ASoIaF is in most other ways, the wights are (cosmetically) very similar those in Tolkien, right down to the fact that in their first appearance a hand is chopped off but keeps moving by itself. The underlying mythology is quite different, though.
 * The book series The Last Apprentice describes wights as the corpses of drowned sailors that witches bind souls to for sinister purposes. They are usually blind, but have very good hearing, and are fast and strong.
 * The Runelords has wights as a type of mage/ghost. It is deadly to touch them as they will freeze you; almost dies from trying to kill one, which is possible in that universe.

Oral Tradition, Folklore, Myths and Legends

 * In Norse Mythology, "Wights" (Vaettir) essentially means Differently-Powered Individual - the term covers any non-divine magical beings, including Elves, Dwarfs, Giants and Trolls.

Tabletop Games

 * Warhammer Fantasy Battle Wights are dead knights and guardians of ancient kings; essentially, the Praetorian Guard of an Undead army. In a possible inspiration from Tolkien, they have health-draining weapons.
 * There is an Isle of Wights off the south coast of Albion (which is a Shout-Out to the Real Life Isle of Wight off the south coast of Britain).
 * Dungeons & Dragons borrowed the wight from Tolkien and made it an undead monster that drained energy levels (Character Levels) from its victims and was created by draining a character of all their levels.
 * The small-press RPG Nightlife had wights (spelled "wyghts") as a PC race, which resembled dried-up human corpses and could drain the youth from victims by touch.
 * The Yu-Gi-Oh! card "Skull Servant" is called "Wight" in the original Japanese version. Interestingly, it eventually gained support cards over the years: notably, "The Lady in Wight" and "Wightmare" kept the "Wight" name in the U.S..

Video Games

 * Nethack runs with the Dungeons & Dragons depiction, giving wights an attack that drains character levels. Interestingly, when eaten, they.
 * The Wights of Fire Emblem: The Sacred Stones are a monster class which functions as a stronger Palette Swap of the Bonewalker class: here, they are reanimated skeleton warriors wielding various weapons.
 * Dragon Age has a version of wight which is basically a teleporting ghost.
 * In the first Kingdom Hearts game, in the Halloweentown world, there are Wight Knights, undead enemies that can best be described as mummies with super-long arms and massive claws.
 * The adventure game The Heroes of Karn had a barrowwight in a place called "the long barrow". No description of it is given, but it can be killed using a bible.
 * Might and Magic 7. Wights, wraiths and barrow wights (in order of increasing power) are a somewhat rare sort of undead that wear long brown robes and tote really nasty knives. Aging, spell point drain and magical terror may result from their attacks.
 * And by 'Somewhat rare' we mean 'You fight them every ten feet in The Barrow Downs. And less often in other areas too.'
 * Similar to the Dungeons & Dragons wights, Exile and Avernum have wights that are higher-level undead who drain experience on hitting.
 * Wights in Myth are zombies that explode when attacked or when they get close to enemies, and spray a paralyzing toxin over nearby units.
 * In Morrowind, "heartwight" is an alternate name for an ash vampire. It fits better, since they aren't vampires at all.
 * In World of Warcraft, Wights are one of the rarer types of Undead in the Scourge. They appear as zombies mutated to monstrous sizes, though are otherwise fairly unremarkable.
 * In Castlevania: Portrait of Ruin, the wight is the name given to a stronger enemy that appears when you defeat several ghouls in an area. As for ghouls, they are only a Palette Swap of zombies.