Eons ago, before life had began on earth, otherwordly creatures ruled over the planet. Eldritch beeing from behind the stars.
They had bodies unlike any mortal beeing, ghostly bodies with twisted proportional and distubing frigtening anatomy and Features. Their astral bodies did not feed on meat or plant matter, they were feeeding from the fear, dispair and sadness of the early humans and animals.

These feared monsters were named "Nightmares" by the humans

But with time, the primal humans advanced. learning to fight against their fears, comforting each other and believing in their hopes and dreams.

With the dreams lf humans getting bigger and stronger, the otherworldy beeings hadn't much negative energy to feed from to continue their reign.
Only the lifeless deepths could harbour the beasts, so they fled into the unknown.

Today, only one of these ancient beeings survived, the powerful nightmare Leviathan. Learning to adopt to this new world and feeding of the anxety and dispair of modern socety. Even making Deals with humans who spread Dear and disaster in the beasts name.

Durring day, this Leviathan like creature wanders around in the undiscovered deephts of the Ocean.
At night, it rises from the sea to roam around in the dreams of humans, hoping to usher age of nighmares once again one day.