Ancient, powerful creatures whose origins lie in the distant past of the cosmos, no two Great Old Ones are exactly alike, although they tend to share similar traits. Most are colossal monstrosities formed from the very fabric of the universe and virtually impossible to destroy, have minds whose thought processes are incomprehensible to humans, show little to no regard for the consequences their actions may have on lesser beings, and drive to insanity any who look upon their true form. In addition, the majority of them are able to influence the minds of sentient creatures even when sleeping or dormant. Initially believed to have been merely indifferent to the fates of those unfortunate enough to be around them, recent writings have shown the majority of them to be actively hostile to the mortal population of the cosmos.
Many of the Great Old Ones are worshiped as gods by mortal cults, both human and otherwise. These cults can be utilised by a Great Old One in a number of ways: some are dedicated to the spread of the Great Old One's influence, others seek to expand the beings' coven of servants, while still more simply wish to see their master freed from imprisonment. For the most part, these cults have no real understanding of the nature of the entity which they hold in such reverence.
Generally speaking, Great Old Ones are limited in their activities to the world on which they inhabit, but a few are capable of extending their reach across the gulf of space to planets orbiting other stars, especially when the object of their attentions is visible in the night sky. Occasionally, the ritualistic services of their respective cults are of assistance in this matter.
The Great Old Ones are considered by many who know of their existence to have individual affinities to the elements of Earth, Air, Fire, and Water.