That is not dead which can eternal lie,
And with strange aeons even death may die.
—Abdul Alhazred, The Necronomicon
The Great Old Ones are ancient extraterrestrial beings of immense power, and most are also colossal in size. These entities seem to have a physical shape, but being cosmic lifeforms from beyond our space-time continuum means they are not based on matter in our definition of the concept, yet their forms are built on principles similar enough to those of true matter that they appear to be material in their nature. They are worshipped by deranged human cults, as well as by most of the non-human races of the mythos. The Great Old Ones are currently imprisoned—a few beneath the sea, some inside the Earth, and still others in distant planetary systems and beyond. The reason for their captivity is not known, though there are two prevailing theories:
According to the first theory, the Great Old Ones were once related to the Elder Gods. When they committed some unknown blasphemy, they were cast out and imprisoned in various places in the universe. The Great Old Ones impatiently await the time of their release, eager to seek retribution against their jailors.
The second theory holds that the Great Old Ones are intentionally dormant. To account for this, it is possible that the universe experiences cosmic cycles, similar to the natural seasons which occur on earth. Just as some animals hibernate during the winter, so too must the Great Old Ones rest in a death-like sleep during the present cosmic cycle. If this is so, the Great Old Ones are currently trapped by powerful cosmic forces and must remain so until such time as the planets are in a certain alignment... or "the stars are right"—the event upon which they may be released and can revel once more across the cosmos.
This table is organized as follows:
| Name | Epithet(s), other name(s) | Description | References |
|---|---|---|---|
| Aphoom-Zhah | The Cold Flame, Lord of the Pole | Appears as a vast, cold, grey flame. | AF, HG, LP |
| Arwassa | The Silent Shouter on the Hill | A vast, wailing, floating monstrosity. | rpg |
| Atlach-Nacha | The Spider God, Spinner in Darkness | A giant spider with a human-like face. | PS, AT,SG |
| Baoht Z'uqqa-Mogg | The Bringer of Pestilence | A huge, flying, scorpion-like beast. | rpg |
| Basatan | Master of the Crabs | ? | MC |
| Bokrug | The Great Water Lizard, The Doom of Sarnath | Appears as a giant lizard. | DC, SC |
| Bugg-Shash | The Black One, The Filler of Space, He Who Comes in the Dark | Appears as a slimy mass covered with eyes and mouths. | DI, EL, KB, RS |
| Byatis | The Berkeley Toad, The Serpent-Bearded | Appears as a gigantic, spider-like crab with a proboscis. | BY, RC, SF |
| Chaugnar Faugn | Horror from the Hills, The Feeder, Caug-Narfagn | An elephant-headed humanoid. | HF, HM, FO, RH |
| Cthugha | The Living Flame, The Burning One | Appears as a living ball of fire. | DD, EL, HC, LM |
| Cthulhu | The Sleeping God, Master of R'lyeh, The Great Priest, Kthulhut, Tulu | A gigantic, winged, octopus-headed humanoid. | AM, BI, CC, FH, GU, HC, HM, LY, MO, PS, RH, SE, TU, YT? |
| Cthylla | Secret Daughter of Cthulhu | Appears as a huge, octopus-like creature. | ID, TC |
| Cxaxukluth | | Probably appears similar to Azathoth. | FT, TA |
| Cyäegha | The Destroying Eye, The Waiting Dark | Appears as a gigantic eye covered with tentacles. | DM |
| Cynothoglys | The Mortician God, She Whose Hand Embalms | Appears as a shapeless, mutating entity with a single arm. | PR |
| The Dweller in the Gulf | Eidolon of the Blind | Appears as a huge, eyeless reptilian creature with whip-like tails. | WL |
| Eihort | The Pale Beast, God of the Labyrinth | Appears as a huge, pallid, gelatinous oval with a myriad legs and multiple eyes. | BS, FP |
| Father Dagon and Mother Hydra | | Both appear as abnormally large Deep Ones. | DA, DB, RD, SI |
| Ghadamon | A Seed of Azathoth | A shapeless, inky, protoplasmic mass. | rpg |
| Ghatanothoa | The Usurper, God of the Volcano | amorphous with multifarious appendages and grotesque members; too horrid to behold, viewing causes petrification. | HT, OE, RL, SX, TP |
| Ghisguth | The Sound of the Deep Waters | Appears as a monstrous whale, sixty feet long, with two massive tentacles replacing its tongue. | FT |
| Glaaki | The Inhabitant of the Lake, Lord of Dead Dreams | Appears as a giant slug with metallic spines. | GL, IB, IL |
| Ghluun | The Corrupter of Flesh, Master of the Temple | Manifests through a Dionysian sculpture; resembles a monstrous sea slug. | TE |
| Gol-goroth | Golgoroth, Gol-Goroth, The Forgotten Old One, God of the Black Stone | Appears as a gigantic, black, toad-like creature with an impossibly malevolent glare. | FO, FR, GB |
| Hastur | The Unspeakable, He Who is Not to be Named, Lord of Interstellar Spaces, The King in Yellow | "True" form remains a mystery; said to be amorphous, possibly octopoid. | FA, HS, LT, RH, SS, WD, YS |
| Hziulquoigmnzhah | | Has spheroid body, elongated arms, short legs, and a pendulum-like head dangling underneath. | DS, FT, TA |
| Idh-yaa | | | OA |
| Iod | The Shining Hunter | A levitating, sinuous, glowing creature. | HU, IN, SZ |
| Ithaqua | The Wind Walker, The Wendigo, God of the Cold White Silence | A horrifying frozen giant. | BW, CD, IM, IQ, SW, TW, WE |
| Juk-Shabb | God of Yekub | Appears as a great ball of energy. | CF |
| Kag’Naru of the Air | ? | ? | ? |
| Kassogtha | ? | ? | ? |
| Lloigor | See Zhar and Lloigor below. | ||
| M'Nagalah the Eternal | The Great God Cancer, The All-Consuming | A massive, tumorous, blob-like thing. | TU |
| Mnomquah | Lord of the Black Lake | A very large and eyeless lizard-creature with a "crown" of feelers. | MD, MQ, SB |
| Mordiggian | The Charnel God, The Great Ghoul, Lord of Zul-Bha-Sair | A horrifying giant with eyeless head and limbless body, much like a worm. | CG, IC, RE |
| Nug and Yeb | The Twin Blasphemies | Appear similar to Shub-Niggurath. | BF, EH, LA, OA, TO |
| Nyogtha | The Thing which Should Not Be, Haunter of the Red Abyss | Appears as an inky shadow. | AF, HG, SH, SR |
| Oorn | ? | Appears as a huge, tentacled mollusc. | MD |
| Othuum | Deep Slumberer in Green, Great Master of Those-Who-Wait-Without | Black, cyclops-like demon with two pairs of legs. | OT, RS |
| Othuyeg | The Doom-Walker | Appears as a great, tentacled eye (similar to Cyäegha). | DF, VC, SP |
| Quachil Uttaus | Treader of the Dust | Appears as a miniature, wrinkled mummy with ankylosed, outstretched claws. | KU, RU |
| Q'yth-az | ? | A crystalline entity. | EF |
| Rh’Thulla of the Wind | ? | ? | ? |
| Rhan-Tegoth | He of the Ivory Throne | A tall humanoid with crab-like appendages; hard to describe in a few words. | HM, AF, LT, RR, PD |
| Rlim Shaikorth | The White Worm | A gigantic, whitish worm with a huge maw and eyes made of dripping globules of blood. | CW, HG, LP |
| Saa'itii | The Hogge | A giant, spectral hog. | |
| Sfatlicllp | | | FT |
| Shathak | Mistress of the Abyssmal Slime, Death Reborn, Mother of the Kraken | Appears as a seventy-foot long kraken with twenty-foot-long massive tentacles | FT |
| Shudde M'ell | The Burrower Beneath, The Great Chthonian | Appears as a colossal worm with anterior tentacles. | BU, CS, TC, WU |
| Summanus | Monarch of Night, The Terror that Walketh in Darkness | A mouthless, grotesque human with tentacles. | FH, WG |
| Tsathoggua | The Sleeper of N'kai, The Toad-God, Zhothaqqua, Sadagowah | Appears as a huge, furry, almost humanoid toad. | BC, DS, FT, IU, OL, RT, SG, TS |
| Ut'ulls-Hr'her | ? | ? | ? |
| Vulthoom | The Sleeper of Ravermos, Gsarthotegga | May appear as a monstrous plant with an enormous, elf-like blossom. | VU |
| The Worm that Gnaws in the Night | Doom of Shaggai | A massive, worm-like fiend. | AG |
| X'chll'at-aa | Lord of the Great Old Ones, The Unborn God, Enemy of All That Live | Appears as a large, black or translucent-skinned creature somewhat like a humanoid embryo with enormous eyes, six arms, and a set of octopoid tentacles in place of legs. | rpg |
| Y'golonac | The Defiler | Appears as a naked, headless human with a mouth in the palm of each hand; other features are nebulous. | CP |
| Yhoundeh | The Elk Goddess | Perhaps an elk-like humanoid. | DS, LE |
| Yibb-Tstll | The Patient One, The Watcher in the Glade | Gigantic, bat-winged humanoid with detached eyes; truly horrible to behold. | CB, OK, SC |
| Yig | Father of Serpents | A scaly, serpent-like humanoid. | CY, SJ, VY |
| Ythogtha | The Thing in the Pit | Appears as a colossal, cyclops-like Deep One. | OA, PD, TC, TP |
| Zathog | The Confuser, the Tempter of Those Who Search in Envy | Appears as a dark, purple-orange humanoid with a foot-long proboscis, muscular arms, antelope horns and a glowing green aura | FB, WZ |
| Zhar and Lloigor | The Twin Obscenities | Both appear as a colossal mass of tentacles (have a rumoured triplet). | SA, LS, TP, SX |
| Zoth-Ommog | Dweller in the Deeps | A gigantic entity with a cone-shaped body, a reptilian head, and starfish-like arms. | HG, OA, TC |
| Zstylzhemghi | Matriarch of Swarms, Zystulzhemgni | ? | FT, TA |
| Zushakon | Dark Silent One, Old Night, Zul-Che-Quon, Zuchequon | Appears as a swirling, black vortex. | BH, KD |
| Zvilpogghua | Feaster from the Stars, The Sky-Devil, Ossadagowah | Winged, tentacle-faced, toad-like giant. | LT, RM, SV |