The attercop split from the grendelsaur and has taken completely to the trees. It now occupies Huggs Temperate Forest and Huggs Rainforest. Eight of the attercop's legs have become much more defined, allowing excellent purchase on even a vertical surface. The two front claws have further developed into large bonesycthes to overpower prey items. The tail claws have shifted into a circular array and can be used to grip or dig into the upper parts of trees. They have become smaller, but are just as long as their ancestor to facilitate their arboreal lifestyle. Their ears have continued to develop and they can recognize creatures by the sounds they make.
The attercop will prey upon arboreal and flying organisms which rest in trees. This includes some of the smaller mega worms on the sides of crystal solar towers. They will try to climb to a higher height than their prey, secure themselves to the tree with their tail claws and leap down on their prey stabbing with its legs and bonescythes. If there is no higher point to attack from, they will try to sneak up on their prey and kill it or knock it out with its bonescythes. They quickly grip the prey before it falls off the tree. They still eat carrion, but only if it is within easy reach of a safe tree.
Attercops are more social than their ancestor and individuals living in the same area will rest in the same place. They still spread out to hunt alone but will protect each other when in their rest area. Males still use their first large fin to display to females during the mating season but do not fight each other; it is the female's choice. Females will lay their eggs into a communal nest made in a tree in the groups rest area, and every adult attercop that rests there will watch over the eggs, with always at least one staying there. The young attercops instinctively know how to hunt when they hatch and will begin hunting soon after. If there are too many Attercops in one area, some of the larger ones will move to other areas.