This was not based off of anything racist, this avatar of Nyarlathotep was based of the Puritan version of Lucifer.

Instead of being described as handsome angel or a ugly goat thing, the Puritans described Lucifer to be a tall lean man with unnaturally charcoal-black skin clad in a black formless robe that haunts the forest and tempts people into witchcraft. He carries with him a black blook filled with the signatures of the heathens that signed it with their own blood.