Cthulhu is described as the ruler and high priest of his kind, and able to garner and maintain human followers through dream projection while asleep/comatose in his city of R’lyeh, immersed beneath the Pacific Ocean.
Cthulhu is a member of a group of beings, all immortal and extremely powerful, referred to as the Great Old Ones. The two other primary classes of entities in this mythology are the Elder Gods, and the Outer Gods, however the nature of these two groups is largely not within the scope of this essay. The same is true of the rest of the Great Old Ones.
More recently, these distinctions have been viewed as unnecessary.