The Call of Cthulhu is the origin of the Cthulhu mythos, (well, if you discount Dagon) HP Lovecraft's seminal work and his most lasting legacy to the horror world. Cthulhu being the octopus-dragon-alien-man that sits dead but dreaming in the undersea city of Ry'leh. The macabre tone and existential horror of Lovecraft's works inspired Chaosium Games to create the Call of Cthulhu roleplaying game, in which the players are investigators arrayed against the impossible odds of the strange things that lurk beyond the veil of the mundane.