[Orofacion of the Vanyar]

Perhaps I was a little too presumptious. Let me clariffy. It is my opinion that Ungoliant was a corrupt maiar. In truth, Ungoliant is almost a sort of evil counterpart to Tom Bombadil in that she is an enigma. We really don't know what her origins are. But according to this quote:

...and that in the beginning she was one of those that he corrupted to his service.

This is where I draw my conclusion from. It sounds alot like the description Tolkien gives for the Balrogs. Just my observations.