These creepy beasts most likely evolved from colony spiders, as evidenced by their social behaviour and vestigial ability to make webs. Incorporating Hellerium metabolism allowed them to grow to huge size. To make things worse, it also increased their intelligence and aggressiveness. Their hunting packs lack any kind of visible hierarchy, but nonetheless appear very well coordinated; there are several tactical roles in such a pack, and individual spiders assume them quite fluidly, depending on the situation, their comparative ability and their mood.