|Title(s)||The Wormgod, the Bonemaster, the Herald of the Age of Worms|
|Home plane||Prime Material|
|Portfolio||Creation and Mastery of the Undead, Decay, Unholy Transformation, Worms|
|Domains||Death, Destruction, Evil, Corruption|
In the World of Greyhawk campaign setting for the Dungeons & Dragons fantasy role-playing game, Kyuss (pronounced "Kai-uhs") is a demigod concerned with the creation and mastery of the Undead. Known as the Bonemaster, the Wormgod, the Worm that Walks and the Herald of the Age of Worms, his symbol is a skull erupting with writhing green worms.
The sons of Kyuss, later referred to as spawn of Kyuss, were an iconic monster in the Dungeons & Dragons roleplaying game before the story of Kyuss was fleshed out. Kyuss was described as "an evil high priest who created the first of these creatures, via a special curse, under instruction from an evil deity" within their creature in the first edition Fiend Folio (1981).
Hints at Kyuss's origins were added in the adventure Rary the Traitor (1992), when sons of Kyuss were said to be contained in the Necropolis of Unaagh, a cursed city of Sulm inhabited by undead. This was made more conspicuous since any of the contained undead that "move or are carried even a few yards from its buildings collapse into inanimate heaps of bone." This is suggested in the work to be the possible consequence of an ancient curse. That makes the creator of the undead ancient as well, painting Kyuss as once having been a high priest in Sulm.
In the From the Ashes boxed set (Atlas of the Flanaess, page 69), the entry for the Storm Lake of the Amedio mentioned that sons of Kyuss manifest in the vicinity after a phenomenon called the Storm of Unknowing.
Still later, in The Scarlet Brotherhood by Sean K. Reynolds, the entry for Matreyus Lake said, "undead such as sons of Kyuss walk the nearby jungle - the evil demigod is said to have spent time here."
In his divine form, Kyuss appears as a towering humanoid shaped entirely of green Kyuss worms, with two blazing eyes peering from beneath the hood of his ragged cloak. According to the Kyuss sidebar in Dragon #336's "Ecology of the Spawn of Kyuss", his original divine form was a gaunt man with empty eyesockets filled with writhing worms and hands of bare bone, but he has evolved into his appearance of a gargantuan Worms That Walk as his cult grew stronger.
Though Kyuss revered Nerull as a mortal, his current relationship with the Reaper is unknown.
Kyuss's faithful believe that life is an obscenity, albeit a temporary one, and that Death offers only nothingness. Undeath, then, is the only worthwhile goal, and followers of Kyuss are encouraged to spread this gift as far as they can. They are permitted to control them if necessary, but encouraged to set them free to do as they will when their creators have no further use. Undead are sacred to Kyuss, and his followers are not permitted to destroy them except in self-defense.
According to the sidebar on Kyuss in Dragon #336's "Ecology of the Spawn of Kyuss", the most important prayer to Kyuss offered by his cultists is a personal act performed once each month, in which they ingest living worms as a sign of their faith.
Clerics of Kyuss raid graveyards to create undead, selling their creations or letting them run wild. The more powerful ones seek to create new kinds of undead, and seek lichdom or some other form of undeath for themselves. They seek to free their master, and travel to various places holy to their faith such as the Wormcrawl Fissure, the Necropolis of Unaagh, or the ruins of Kuluth-Mar.
According to the sidebar on Kyuss in Dragon #336's "Ecology of the Spawn of Kyuss", Kyuss's clerics are initiated in a deadly rite called "First Ingestion", in which they drink a Potion of Inflict Light Wounds containing a preserved Kyuss Worm.
Once a human priest of Nerull in the Flan kingdom of Sulm, Kyuss escaped that realm shortly before its destruction by fleeing to the Amedio Jungle, when he gained many followers. Kyuss later went to the Spire of Long Shadows, where he sacrificed all of his followers to achieve hero-deityhood. Prior to this, he had sacrificed artifacts of great power, as well as living souls to Nerull in order to gain his favor. When he finally did ascend, there was a small problem with his transformation: he became trapped in the same obelisk with which he channeled his power. It is speculated that Nerull, not wanting to be challenged, even slightly, flawed the ritual somewhat, thus leading to Kyuss's imprisonment.
Even during his imprisonment, he gained following from some very powerful followers. Dragotha, a wyrm red dragon, was allowed by Kyuss to attain the form of a dracolich. Following this, Dragotha was bound to serve Kyuss, and in the process became his herald. Another draconic follower of Kyuss is Lashonna, a vampiric silver dragon.
Kyuss is responsible for the creation of the spawn of Kyuss, also known as sons of Kyuss, though these are said to be the least powerful of his creations. He is also believed to be responsible for the creation of the avolakia, eviscerator beetle, ulgurstasta, Kyuss knight, overworm, earthcancer centipede, hound of Kyuss, sword of Kyuss, wormcaller, worm naga, wormswarm, and the worm that walks. Collectively, his creations are known as wormspawn.
Influence on popular culture
- Turnbull, Don, ed. Fiend Folio. Lake Geneva, WI: TSR, 1981
- Pryor, Anthony. Rary the Traitor (TSR, 1992)
- Sargent, Carl. Iuz the Evil (TSR, 1993)
- Jacobs, James. "The Ecology of the Spawn of Kyuss." Dragon #336 (Paizo Publishing, 2005)
- Rivadavia, Eduardo. "Kyuss Biography". All Music. Retrieved 2007-07-04.
- Baur, Wolfgang. "A Gathering of Winds." Dungeon #129 (Paizo Publishing, 2005).
- Breault, Mike. Monstrous Compendium Greyhawk Adventures Appendix (TSR, 1990).
- Bulmahn, Jason. "The Hall of Harsh reflection." Dungeon #127 (Paizo Publishing, 2005).
- Conforti, Steven, ed. Living Greyhawk Official Listing of Deities for Use in the Campaign, version 2.0 (Wizards of the Coast, 2005). Available online: 
- Cordell, Bruce, Eytan Bernstein, Brian James, Robin Laws, and John Snead. Open Grave: Secrets of the Undead. Renton, WA: Wizards of the Coast, 2009. excerpts
- Decker, Jesse. "The Spire of Long Shadows." Dungeon #130 (Paizo Publishing, 2006).
- Decker, Jesse. "Worm Bound: The Secrets of Kyuss." Dragon #343 (Paizo Publishing, 2006).
- Jacobs, James. "Into the Wormcrawl Fissure." Dungeon #134 (Pazio Publishing, 2006).
- Leati, Tito. "The Champion's Belt." Dungeon #128 (Paizo Publishing, 2006).
- Leati, Tito. "Dawn of a New Age." Dungeon #135 (Paizo Publishing, 2006).
- Logue, Nicholas. "The Library of Last resort." Dungeon #132 (Paizo Publishing, 2006).
- Mearls, Mike. "The Three Faces of Evil. Dungeon #125 (Paizo Publishing, 2005).
- Mona, Erik. Age of Worms Overload (Paizo Publishing, 2005). 
- Pett, Richard. "The Prince of Redhand." Dungeon #131 (Paizo Publishing, 2006).
- Reynolds, Sean K. "Encounter at Blackwall Keep." Dungeon #126 (Paizo Publishing, 2005).
- Reynolds, Sean K, Frederick Weining, and Erik Mona. "Blood of Heroes." Living Greyhawk Journal #3 (Paizo Publishing, 2001).
- Schwalb, Robert J. Elder Evils. Renton, WA: Wizards of the Coast, 2007.
- "Kyuss's Ascension to Divinity" at Canonfire!.
- "Mellifleur and Kyuss" at Canonfire!.
- "The Origins of Kyuss" at Canonfire!.
- Kyuss at the Greyhawk wiki.