- "That is not dead which can eternal lie,
And with strange aeons even death may die."
- ―Abdul Alhazred, Necronomicon
Cthulhu is a giant cosmic entity with the head of an octopus, rubbery skin, prodigious claws on his hands and feet, and long narrow wings on his back. His name might be derived from the Classical Greek word "chthonic", meaning "subterranean"; although he's been more commonly associated with the water element.
Cthulhu serves the high-priest and leader of a race of land-based octopus-like creatures which have come from the skies to colonize Earth in prehistory. Although currently in a deathlike state of hibernation at the bottom of the ocean, Cthulhu and his alien brethren can still manifest themselves in the minds of some people, and are predicted to be revived once the stars are in the right conformation.
Little is known about Cthulhu's origins, other than he's the offspring of a being called Nug and the grandchild of the Outer Gods Yog-Sothoth and Shub-Niggurath - both of which are grandchildren of the primordial Azathoth, who created the universe.
Cthulhu is a gigantic humanoid with both cephalopod and draconian features and the ability to heal body damage. His size has been compared to a mountain. He is perhaps most notable for the deeply disruptive effects that his physical or mental presence may have in the minds of Humans. A mere gaze of his physical form may easily induce insanity and even death for the unfortunate witness. Even from his sunken tomb in R'lyeh, in the Pacific Ocean, Cthulhu can manifest his presence in the subconscious minds of particularly sensitive people, especially cultists, madmen and artists. The most frequent manifestation occurs in the form of nightmares.
Since few who actually saw Cthulhu have survived the encounter and retained their sanity intact, the most detailed descriptions are based on statues or idols of the creature. One, constructed by an artist after a series of baleful dreams, is said to have "yielded simultaneous pictures of an octopus, a dragon, and a human caricature.... A pulpy, tentacled head surmounted a grotesque and scaly body with rudimentary wings". Another, recovered by police from a raid on a murderous cult, "represented a monster of vaguely anthropoid outline, but with an octopus-like head whose face was a mass of feelers, a scaly, rubbery-looking body, prodigious claws on hind and fore feet, and long, narrow wings behind".
At some point in the Paleozoic Era, Cthulhu arrived on Earth along with his escort of alien followers who built stone cities of non-euclidean architecture and fought long-standing wars against another alien race known as the Elder Things.
The secret cult of Cthulhu is extremely ancient and spread throughout the globe, from New Zealand to Greenland, from the USA to China. Mention has been made of the "undying leaders of the cult in the mountains of China". Cultists believe that "the Great Old Ones" will liberate them from law and morals, and their rituals are noted as disturbingly animalistic, wild and even murderous. It should be noted, however, that the expression "Great Old Ones" here refers to the Spawn of Cthulhu and not to the pantheon that he belongs to.
In addition to this Human cult, Cthulhu is also worshiped by aquatic Deep Ones and might be related to, or even represent the same entity as their god Dagon (although most evidence points out that Dagon is simply a gigantic Deep One).
The rituals of the cult of Cthulhu notably involve the chanting of the phrase "Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn", which is translated as "In his house at R'lyeh dead Cthulhu waits dreaming". The phrase can also be shortened to just "Cthulhu fhtagn".
According to the cultist known as Old Castro, Cthulhu and his star spawn (which Castro refers to as "Great Old Ones") have come from the stars and built their cities long before the advent of mankind. He also claims that, although they have a physical shape, they're not made of matter, which explains their extraordinary abilities. It is believed that, when the stars are arranged in a certain way, they can hop effortlessly from one world to another. Conversely, when the stars are not in that right conformation they cannot live, but are unable to truly die either so instead they remain in a state that the cultists refer to as death, but which more closely resembles a form of stasis, hibernation or cryptobiosis. Even in that state, they can still be perceived and manifest themselves in the minds of men, especially those artistically inclined - poets, sculptors, architects, etc.
- "These Great Old Ones, Castro continued, were not composed altogether of flesh and blood. They had shape - for did not this star-fashioned image prove it? - but that shape was not made of matter. When the stars were right, They could plunge from world to world through the sky; but when the stars were wrong, They could not live. But although They no longer lived, They would never really die. They all lay in stone houses in Their great city of R'lyeh, preserved by the spells of mighty Cthulhu for a glorious resurrection when the stars and the earth might once more be ready for Them. But at that time some force from outside must serve to liberate Their bodies. The spells that preserved Them intact likewise prevented Them from making an initial move, and They could only lie awake in the dark and think whilst uncounted millions of years rolled by. They knew all that was occurring in the universe, but Their mode of speech was transmitted thought. Even now They talked in Their tombs. When, after infinities of chaos, the first men came, the Great Old Ones spoke to the sensitive among them by moulding their dreams; for only thus could Their language reach the fleshly minds of mammals."
- ―Francis Wayland Thurston, relating what Old Castro told Inspector Legrasse in 1907.
In his studies of the occult, Albert Wilmarth claimed that he learned "whence Cthulhu first came, and why half the great temporary stars of history had flared forth". On a latter addressed to Wilmarth, Henry Akeley referred to "the fearful myths antedating the coming of man to the Earth - the Yog-Sothoth and Cthulhu cycles - which are hinted at in the Necronomicon". He also found that Cthulhu is among the entities worshiped by the alien Mi-Go race, which share the Spawn of Cthulhu's unknown material compositions and are referred to by some Humans as "the old ones".
The claim that the Cthulhu spawn have colonized Earth in prehistory and that they're not made of ordinary matter is latter corroborated by imagery found in the prehuman ruins of the alien Elder Things in Antarctica, which are enemies of both the Mi-Go and the Spawn of Cthulhu.
- "The Call of Cthulhu", by H. P. Lovecraft (1928) (First appearance)
- "The Dunwich Horror", by H. P. Lovecraft (1929) (Mentioned only)
- "The Shadow Over Innsmouth", by H. P. Lovecraft (1931) (Mentioned only)
- "The Whisperer in Darkness", by H. P. Lovecraft (1931) (Mentioned only)
- "Ubbo-Sathla", by Clark Ashton Smith (1933) (Mentioned only)
- "The Horror in the Museum", by H. P. Lovecraft (1933) (Mentioned only)
- "Through the Gates of the Silver Key", by H. P. Lovecraft and E. Hoffmann Price (1934) (Mentioned only)
- At the Mountains of Madness, by H. P. Lovecraft (1936) (Mentioned only)
- "History of the Necronomicon", by H. P. Lovecraft (1938) (Mentioned only)
- "The Mound", by H. P. Lovecraft (1940) (Mentioned only)
- "The Lurker at the Threshold", by August Derleth and H. P. Lovecraft (1945) (Mentioned only)
- After being introduced in the short story "The Call of Cthulhu", published in the American pulp magazine Weird Tales in 1928; Cthulhu became the most well-known figure in the mythology of author H. P. Lovecraft; and is often cited for the extreme descriptions given of his hideous appearance, his gargantuan size, and the abject terror that his presence evokes.
- August Derleth, a correspondent of Lovecraft's, used the creature's name to identify the system of lore employed by Lovecraft and his literary successors: the Cthulhu Mythos.
- The fact that the Spawn of Cthulhu have been consistently referred to as the "Great Old Ones" in the original tale is prone to generate some confusion, given that that term has since been popularized with a different meaning. As used today, the term "Great Old Ones" usually refers to the pantheon of supernatural deities of which Cthulhu himself is one. Based on the information provided in At the Mountains of Madness, it is clear that the beings Old Castro refers to as the "Great Old Ones" are nothing more than the race of land-based octopus-like aliens, better known today as the "Spawn of Cthulhu" ("They all lay in stone houses in Their great city of R'lyeh, preserved by the spells of mighty Cthulhu", he claims).
- Elsewhere in Lovecraft's fiction, Cthulhu has been occasionally described in ways that appear to contradict information given in "The Call of Cthulhu". For example, rather than including Cthulhu among the Great Old Ones, a quotation from the Necronomicon in "The Dunwich Horror" says of the Old Ones: "Great Cthulhu is Their cousin, yet can he spy Them only dimly".
- It's important to note that Lovecraft has used the term "Old Ones" to refer to many different entities throughout his fiction. The Elder Things of Antarctica are consistently referred to as the "Old Ones", and that same term has even been applied to the Mi-Go, which are wholly different creatures and in fact one of the Elder Things' enemies.
- In a 1933 letter addressed to James F. Morton, Lovecraft himself has drawn a fanciful genealogical tree for Cthulhu, which reveals that the creature is a direct descendant of the Outer Gods via an entity called "Nug", and an ancestor of Shaurash-ho, Yogash the Ghoul, K'baa the Serpent, Ghoth the Burrower, Llunwy of Wales, Owen Gwynedd and Lovecraft himself.
- Meanwhile, Nug's sibling, "Yeb" is the progenitor of Tsathoggua, whose descendants include Lovecraft's friend (and Tsathoggua's creator) Clark Ashton Smith. This is probably due to the fact that Cthulhu and Tsathoggua are the most famous and oft-referenced creations of Lovecraft and Smith, respectively.
- Cthulhu is also a genus of symbiotic protozoans which live inside the guts of termites and help them digest food. Additionally, there's also a spider species (Pimoa cthulhu) and a moth species (Speiredonia cthulhui) named after Cthulhu.
- Cthulhu's name has been alternatively spelled as Tulu, Clulu, Clooloo, Cthulu, Cighulu, Cathulu, Kutulu, Q'thulu, Ktulu, Kthulhut, Kulhu, Thu Thu, and in many other ways. It is often preceded by the epithet "Great", "Dead", or "Dread".
- Lovecraft transcribed the pronunciation of Cthulhu as "Khlûl'-hloo" (/kəˈθuːluː/). He said that "the first syllable [of Khlûl'-hloo is] pronounced gutturally and very thickly. The u is about like that in full; and the first syllable is not unlike klul in sound, hence the h represents the guttural thickness".
- S. T. Joshi points out, however, that Lovecraft gave several differing pronunciations on different occasions. According to Lovecraft, this is merely the closest that the human vocal apparatus can come to reproducing the syllables of an alien language.
- Long after Lovecraft's death, the pronunciation kə-THOO-loo (/kəˈθuːluː/) became common, and the game Call of Cthulhu endorsed it.
- Other works in which Cthulhu has appeared include: Afterlife with Archie, the Doctor Who novel White Darkness (unnamed, but later identified in All-Consuming Fire), Dungeons & Dragons, The Real Ghostbusters, and The Grim Adventures of Billy & Mandy.
- Games company TSR included an entire chapter on the Cthulhu mythos (including statistics for the character) in the first printing of Dungeons & Dragons sourcebook Deities & Demigods (1980). TSR, however, were unaware that Arkham House, who asserted copyright on almost all Lovecraft literature, had already licensed the Cthulhu property to the game company Chaosium. Although Chaosium stipulated that TSR could continue to use the material if each future edition featured a published credit to Chaosium, TSR refused and the material was removed from all subsequent editions.
- The character of Cthulhu also inspired many other creatures, such as Robert E. Howard's own creation Yag Khosha, in the short story "Tower of the Elephant" - an early Conan tale.
- In 1937, August Derleth wrote the short story "The Return of Hastur", and proposed two groups of opposed cosmic entities: "the Old or Ancient Ones, the Elder Gods, of cosmic good, and those of cosmic evil, bearing many names, and themselves of different groups, as if associated with the elements and yet transcending them: for there are the Water Beings, hidden in the depths; those of Air that are the primal lurkers beyond time; those of Earth, horrible animate survivors of distant eons". According to Derleth's scheme, "Great Cthulhu is one of the Water Beings" and was engaged in an age-old arch-rivalry with a designated Air elemental, Hastur the Unspeakable, described as Cthulhu's "half-brother".
- Based on this framework, Derleth wrote a series of short stories published in Weird Tales between 1944 and 1952, and collected as The Trail of Cthulhu, depicting the struggle of a Dr. Laban Shrewsbury and his associates against Cthulhu and his minions, and culminating, in "The Black Island" (1952), with the atomic bombing of R'lyeh, which Derleth has moved to the vicinity of Ponape.
- Derleth's interpretations are not universally accepted by enthusiasts of Lovecraft's work, and indeed are criticized by many for injecting a stereotypical conflict between equal forces of objective good and evil into Lovecraft's strictly amoral continuity.
- Cthulhu has served as direct inspiration for many modern artists and sculptors. Prominent artists that produced renderings of this creature include Paul Carrick, Stephen Hickman, Kevin Evans, Dave Carson, Francois Launet and Ursula Vernon.
- Multiple sculptural depictions of Cthulhu exist, one of the most noteworthy being Stephen Hickman's Cthulhu Statue which has been featured in the Spectrum annual and is exhibited in display cabinets in the John Hay Library of Brown University of Providence. This statue of Cthulhu often serves as a separate object of inspiration for many works, most recent of which are the Cthulhu Worshiper Amulets manufactured by a Russian jeweler. For some time, replicas of Hickman's Cthulhu Statuette were produced by Bowen Designs.