The ones we are up against worship moloch. Any alien beings belonging to intelligent e.t. races that mean to enslave us have been called "Satan." I don't think there is truly one grand high evil, and if there is, I don't think we've ever interacted with it directly as a species. I think evil is often misconstrued as having conflicting interests. Is the bear evil because it devours the fish? But a fish that hands his fellow fish over to the bear for money is certainly a motherfucker.