The Great Ones were the gods of the natives of Maltos IV.
In the Book of Fulfillment the natives describe making multiple appeals to the Great Ones to save them from Klingon invaders. The natives see the arrival of James T. Kirk and the USS Enterprise as deliverance provided by the Great Ones. Once the Klingons were driven out and Kirk had departed, the natives made sacrifices to the Great Ones and held a great feast, ending with the consumption of Klingon prisoners. (TOS - Strange New Worlds 9 short story: "Book of Fulfillment")