WHAT IS CTHULHU MYTHOS?
Lovecraft's writings are largely based on a fear of the unknown and unknowable, and he didn't do too much to solidify and set out all of his mythos for the reader.
The universe is a vast, uncaring place. Humans are nothing special. There are alien beings out there that are like gods to us, but they are at best ambivalent, and at worst would just see everything destroyed. They are so far beyond our comprehension that to even see some of them would drive a man mad. Coming from beyond the stars, some of them are hardly even contained by the traditional dimensions, some of them are like occult demons, one is even a messenger who disguises itself as other races, including humans, to walk among us. That last one even once had himself worshiped as a pharaoh of ancient Egypt.
One of them is trapped here on Earth. Due to a peculiar alignment of stars, it lays in a state of torpor deep beneath the Pacific Ocean, awaiting the day the stars align once more and allow it to awaken. Even while it sleeps, it sometimes reaches out to touch the dreams of mankind, whispering into the minds of the insane and creeping through the nightmares of even sane men. Cults of madmen and ancient tribes are dedicated to the worship of this, and other, gods.
There are lesser races too. With biology we cannot even hope to grasp, they may live on moons within our solar system, or be capable of traveling from the furthest reaches of the universe in search of resources and test subjects, or even from beyond time itself. Some even lived here on Earth long ago in the earliest stages of life on our planet, grotesque floating polyp-like monstrosities or bizarre, fungoid beings with their race of shapeless, indescribable servitor beasts, the traces of which have been lost to prehistory.
These things are all interlinked, along with strange alien worlds and dreamscapes, making up the mythos. Even outside of the mythos, the world is a strange place populated by dark sciences akin to magic, beings so evil their own malice has deformed them, and terrible creatures lurking in the dark corners of the Earth, where sane men would do best to pray they remain.
-https:/ /w ww. reddit.co m/r/Lovecraft/comments/2v86jx/can_anyone_explain_me_what_is_the_cthulhu_mythos/
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