330px-Yog-Sothoth couleur
Yog-Sothoth is one of the The Dark Ones, first invented by American horror author H.P. Lovecraft. The being has been specifically mentioned in Evil Dead fiction several times. 

A Dark One

Yog-Sothoth is one of the Dark Ones who ruled the Earth millenia before the creation of the earliest earth creatures. It is one of the beings that hold mastery over the Deadites. This creature, along with the Deadites, was banished to the mirror dimension along with the other Deadites. In Army of Darkness Vs Re-Animator, Yog-Sothoth was nearly unleashed upon the world, but was stopped by Ash Williams.