The Giant Spiders
A kind of arthropod very similar to our "Camel Spiders" but much bigger, they seem to live in small colonies underground where they protect their larvae.
They are ambush hunters and their behavior becomes exceptionally aggressive when they feel that the colony is in danger.
They find a perfect habitat in abandoned buildings
filled with pits or other cavities where they nest. Their exceptional size makes us think that their original environment is richer in oxygen than ours.