Kyuss, also known as the "Worm that Walks," was an Elder evil prophesied to usher in the Age of Worms, a prophecied time when the undead of Oris will rise and destroy the world.


The Worm that Walks was a 30 foot (9 meters) tall giant composed of a shifting mass of maggots and worms filled with the psychic imprint of a former demigod named Kyuss.


The true story of the being known as the Worm that Walks remains a mystery to sages and scholars. The only known fact all agreed on was that the Worm that Walks was originally a demigod called Kyuss, who had lived in the ancient past as a mortal necromancer and created many aberrant undead creatures, such as the Spawn of Kyuss that plagued the Underdark.


Eventually, Kyuss' wickedness made his contemporaries to exile him to the fringes of society. Rather than languishing as an outcast, he became the prophet of a wicked cult who believed in the dreaded Age of Worms. During this time Kyuss discovered the ruins of a dead civilization in an unknown island in Dragon Sound, known as the Wormcrawl Island by the Vaas, and claimed the site as its own, where he ruled as a god-king. Kyuss was worshiped in the lost city on the island, known as the Spire of Long Shadows. In the city ruins, his followers discovered ancient metal plates, which held terrible secrets but also confirmed every prophesy he had spoken.

Through these inscriptions, Kyuss discovered how to transcend mortality at a terrible price—the lives of his congregation. On one bloody night he instructed his priests to slaughter them all, and after that Kyuss murdered the priests as well. When he was finished, he fused his essence with the foul ruins, gaining and losing his divinity in one moment. He was neither mortal nor god, and he was bound forever to the ruins. However, he was transformed into something far worse.

Some scholars believed Kyuss originated from the Far Realm. After the Time of Troubles, a coalition of dark cultists called the Ebon Triad uncovered several ancient scrolls regarding Kyuss, and tried to find Wormcrawl Island in hopes Kyuss would resurrect their respective gods.