Saaitii is a fictional entity which made its first appearance in William Hope Hodgson's Thomas Carnacki story "The Hog", although it was unnamed in that work. It was given a proper title and classified as a Great Old One in Chaosium's Call of Cthulhu roleplaying game in 1994, incorporating it into the Cthulhu Mythos proper.
In the original Carnacki stories, the word "Saiitii" (sometimes spelled "Saaitii") is not the name of a single entity, but rather a dangerous class of supernatural manifestations, of which the titular monster from "The Hog" is identified as one. The word first appears in "The House Among the Laurels", and is also used in "The Whistling Room" and "The Hog".
Background[]
Saaitii is a minor Great Old One that resides in an outer realm, full of darkness and labyrinth tunnels. It manifests as a nightmarish swine, with rhino-like flesh covering its bloated, cadaverous form. Which has a tiny cyclopean eye, at least a dozen cloven-hoofed legs, and three maws filled with boar-like teeth and tusks. Saaitii attacks the souls of its victims, first possessing them and then dragging them into its lair where they are devoured.