Cthulhu is the creation of H. P. Lovecraft, an American science fiction writer of the early 20th century. Lovecraft was (and still is) one of the few writers who truly took to heart the immense age and size of the cosmos when writing his stories. In these stories our nearest kin in the galaxy are immeasurably superior to us, and see us at best as slaves and at worst as, well . . . do you remember all the bugs you stepped on today? You get the point. Lovecraft explains supernatural phenomena such as witchcraft and demonic possession as close encounters with some of the "lesser" of these aliens. Real information about the aliens is only archived in texts like the Pnakotic Manuscripts and the Neknonomikon - books filled with such terrible truths that to read them brings the risk of insanity. Lovecraft stories are short, generally under 100 pages. The typical story is a narrative by an investigator of some unusual phenomenon, whether it be an odd occurrence or a patient's mental illness. Through the course of the story the investigator encounters some aspect of the extraterrestrial numinous powers and barely escapes with his life. Many of the stories are centered in or around Arkham, Massachusetts, a proxy for Salem, though the investigations often range world-wide. "The Call of Cthulhu" has become the most famous of his stories because its numinous power, Cthulhu, has supplied its cool-sounding name to the entire Lovecraftian worldview, the "Cthulhu Mythos". "Call" is not the best of the stories, however, and I recommend the following:
"The Case of Charles Dexter Ward" concerns the attempt to explain the insanity of Charles Dexter Ward, and becomes a descent into the sources of the Salem witchcraft legend. In this case, it is not due to the "political incorrectness" of Salem women.
"The Dunwich Horror" concerns odd experiments going on in the backwoods town of Dunwich, which experiments are actually a prelude to an invasion from outside spacetime.
"At the Mountains of Madness" is the tale of the fate of an Antarctic expedition that finds remains of extraordinary things in the ice.
"The Dream Quest of Unknown Kadath" is unlike most of the other tales. It takes place in the Dreamlands, another world that though it too is invaded by Great Powers, there is help and light as well. Watch for the cats.
There is also a collection of poems. Not all are about monsters, though most are, and in one poem the monsters are destroyed by a benificent higher power, though usually we aren't so lucky. Ooh, Nyarlathotep is so bad! Since Lovecraft's death in 1937 several other authors have added to the Cthulhu Mythos. There is an RPG called "Call of Cthulhu" and numerous associated paraphernalia. I own an "Arkham Sanitarium" hospital shirt. You can get bumper stickers that read:
Largely this is all an excuse, I think, to talk about creatures and places with remarkably obnoxious names like Nyarlathotep, Yog Sothoth, Shub Niggurath, Azathoth, Shantak,, Mi-Go, Yuggoth, Yith, Cthuga, and, of course, Cthulhu.
Happy reading.
I wanna go Home!