In the Dungeons & Dragons fantasy role-playing game, an obyrith is a member of an ancient race of demons that predate the tanar'ri. All obyriths have monstrous forms which can drive mad anyone who dares look at them.
The concept of the obyrith type of demon was introduced in the third edition in the Fiendish Codex I: Hordes of the Abyss (2006). This book introduced the ekolid and the sibriex, as well as the demon lord Dagon. The laghathti was introduced on the Wizards of the Coast website in 2006. Dagon, Prince of the Darkened Depths, was detailed in Dragon #349 (November 2006), which introduced the uzollru. The draudnu appeared in Monster Manual V (2007), the Golothoma in Elder Evils and the verakia appeared in Dragon #357 (July 2007).
Heavily reworked obyriths make an appearance in the 4th edition of Dungeons & Dragons. In the Demonomicon supplement, the obyriths are described as entities of unfathomable evil from another universe. After consuming or destroying everything in their universe, the remaining obyriths fashioned all of their hatred and hunger into a single, horrific shard of pure evil, which they used to pierce the veil between universes. The shard was found (in the default D&D universe) by Tharizdun, who was instantly corrupted by its evil and used it to create the Abyss. The twelve surviving Obyriths fled their dying reality and entered the new plane, where they dueled several primordials- the beings who would eventually become the likes of Baphomet, Demogorgon, Orcus, and Yeenoghu- for control. The Abyss warped both the obyriths and the primordials into demon lords. In the new edition, only the Queen of Chaos, Pazuzu, Obox-ob and Dagon are explicitly confirmed as being obyriths; it is left to the DM to decide which of the other demon lords are obyriths.