"Ktulu! / Ktulu's so he-ea-ea-a-avy / he's driving you mad. / He's driving you mad! / He's driving you. / Hyeah! / He's so / Heavy! / Heavy! / Heavy! / Yeah!"
- Ktulu (He's So Heavy) by Beatallica
(Okay, I know it's a dumb quote, but if you're familiar with The Beatles, Metallica, and Lovecraft, the song is pretty awesome.)
Great Cthulhu is the most famous of the Great Old Ones of the Cthulhu Mythos. He's described as huge, immortal, alien, and evil. Maybe I should be saying "it", ascribing a gender to Cthulhu humanizes it too much. The whole point is the alien-ness of this titanic and cthonic monster.
If I say that my somewhat extravagant imagination yielded simultaneous pictures of an octopus, a dragon, and a human caricature, I shall not be unfaithful to the spirit of the thing. A pulpy, tentacled head surmounted a grotesque and scaly body with rudimentary wings; but it was the general outline of the whole which made it most shockingly frightful.
- H.P. Lovecraft, The Call Of Cthulhu
Cthulhu is immortal. It rests at the bottom of the ocean, in a city named R'lyeh, waiting for an opportunity to destroy us all. When The Stars Are Right, it will arise and devour mankind. Or, drive us all mad with it's Alien Geometry. Or consume our souls. Or mutate us into something no longer human. Or maybe just fail to notice us in the same way we fail to notice the ants we displace when we stomp around and build our vast monuments. It's hard to say with Cosmic Horror - you just know Cthulhu's big and bad, and we should all fear his return.
Despite lending his name to numerous role-playing games and the Cthulhu Mythos, ol' squid face isn't actually the center of Lovecraftian Pantheon. Depending on how you look at things, that'd more likely be Nyarlathotep or Azathoth. Cthulhu himself only plays a major role in one of Lovecraft's stories.
Other spellings for Cthulhu include Cathulu, Cighulu, Clooloo, Clulu, Cthulu, Kthulhut, Ktulu, Kulhu, Kutulu, Q’thulu, Thu Thu, and Tulu. I can't possibly list pronounciations - he's the original The Unpronounceable. Our human bodies (and minds) aren't built for his language.
Great Cthulhu is served by all sorts of lesser minions, from depraved human cultists to hybrids known as Deep Ones, to his own huge tentacle-faced spawn. It's a Religion of Evil with Mutation and Monster of the Week subthemes. Given his evil alien nature, he probably doesn't give a hoot about any of them. Cthulhu may be in league with the other Great Old Ones, or an enemy of Hastur, or they may all be so inhuman as to have no identifiable emotions or relationships.
According to August Derleth, Cthulhu is some sort of super-powered Water Elemental. Kenneth Hite says Cthulhu is "the incarnation of (or a sentient facet of) gravity." The Cthulhu Project says Cthulhu is actually a spaceship being built underwater by a vast global conspiracy to leave the planet. For more ideas, see Interpretatio Cthulhiana.
- Global Consciousness Project - This project might detect when Cthulhu stirs in his sleep.
- Event/News: San Diego Menaced By Jumbo Squid - a sign of Cthulhu stirring?
- News: Monster Octopi With Scores Of Extra Tentacles - Cthulhu often mutates and changes his servants…
- Event/News: Undersea eruptions near Tonga - this eruption is too close to R'lyeh for comfort…
Game and Story Use
- For ideas on Cthulhu's physical capabilities, see Eldritch Abomination, Dragon, Octopus, Physical God], Elemental, Titan, Giant and Fourth-Dimensional Lifeform. Anyone who sees him will likely go insane.
- Speaking of which, his psychic abilities include being able to influence dreams across the world, drive artists mad, and guide cults over the millenia while being dead or asleep. Anything's fair game. See Psionics, Magic, Sufficiently Advanced Aliens, Reimann's Bookworms, Fourth Dimension and Alien Geometries.
- Okay, so given all this, if Cthulhu wakes up, unless the PCs are Zeus, Thor, Merlin and Superman, it's game over.
- Any game can be spiced up by a reference to Cthulhu or the Cthulhu Mythos. Have some deranged cultist or mad scientist drop the name, and your players will scramble. Is that NPC crazy, or are we in a different genre than we thought we were?
- The cult of Cthulhu can be at the heart of any conspiracy theory, or explain the motivation of any madman. See With Great Power Comes Great Insanity and These Are Things Man Was Not Meant To Know.