Elder evil

Elder evils were ancient, powerful, and generally evil beings or entities. Their power could rival, or even surpass, that of demigods to such that they could destroy an entire world.

Elder evils
Examples of these beings included Atropus, an undead planetoid said to be the first atropal, a stillborn god; Zargon the Returner, the original lord of the Nine Hells who was cast out by Asmodeus; Father Llymic, a being of intense power from the Far Realm who escaped the plane of madness to destroy the world but was encased in ice by elven mages; Pandorym, an entity from a space between the planes whose mind was imprisoned in a huge crystal, that was called to the world by the ancient Imaskari to intimidate the gods of their slaves. Other beings called Elder Evils include Shothragot and Haask, Voice of Hargut.

Elder Eternal Evils
Three beings described as "Elder Eternal Evils" are Dendar the Night Serpent; Kezef the Chaos Hound; and Ityak-Ortheel, the Elf Eater. Later, Dendar and Kezef were considered primordials.

Aboleth Elder Evils
The aboleth race recognized a class of powerful alien entities who predated the gods and inhabit the Far Realm. Collectively known as the "Elder Evils," these beings generally care nothing for any mortal race, offering only madness and destruction.
 * Bolothamogg, Him Who Watches from Beyond the Stars, was a guardian force that sought to protect the Far Realm from the "taint" of our reality. Bolothamogg had some sort of alliance with the demon lord Areex.
 * Holashner, the Hunger Below, was one of the few Elder Evils to exist fully in the Prime Material Plane. Appearing as part squid and part centipede, this massive creature burrowed through the deepest reaches of the world, driven only by its unending hunger. It ate stone, magma, creatures, and anything else in its path.
 * Piscaethces, the Blood Queen, was the source of the aboleth race, depicted as a vast aboleth with no tentacles and with mucus the color of blood.
 * Shothotugg, the Eater of Worlds, dwelt in a distant corner of the multiverse, physically far removed from the world itself. An undulant mass of seething fluid the size of a mountain, Shothotugg traveled through the gulfs of space from world to world, poisoning and parasitizing any world on which it alighted.
 * Y'chak, the Violet Flame, was unique among the Elder Evils in a terrible way—it was actively interested in the development of life or, to be more precise, in the development of the destruction of life. Its true form was said to be a brilliant pillar of violet flames that concealed an inner form so horrifying that to see it clearly was to invite utter destruction upon the body and soul.