[@Rydude17] They might be, though it is not clear. I do know that in their peak they have made temples to Yig, the Father of Serpents who is also identified with/as(?) Quetzalcoatl who was worshiped by the Aztecs. They would also regularly perform sacrifices to Yig like Aztecs would, but then again basically every cult in the Mythos practices Human (or other, though usually it is just Humans because we must be delicious or something) sacrifices. 

So, we going to go with the whole infiltrating society thing?  If we do, I think I'll change my Char's backstory accordingly a bit though he would not hate Humans and other races but be indifferent.