Cal's Nest

Scattered around the boughs of the world, there are haunted places where branches tangle the tightest. One dark omen in these places are huge masses of dried leaves. These bundles of foliage are tightly packed and woven between twigs, with a black spiral hole leading in. These are the nests Redbelly Cal makes from towns the squirrel has raided.
When the beast takes to a new region, he begins building a nest. Using the lairs to stash his spoils and slumber undisturbed, the nests quickly grow. While he is in the area, Redbelly Cal viciously defends his lair. Few attempts to drive him away from a nest have ever been successful. But for as territorial as the squirrel is, he seems to readily abandon the lair and the stash within when he decides to move on to other parts of the world. The whiplash of aggression to abandonment can feel just as devastating as the attacks, leaving towns dazed and lacking any form of closure.
Despite the seemingly crude construction, the leaf lairs can be quite complex internally. A maze of tunnels with store rooms, false exits, and dark chambers spreads throughout the bundle. All across the walls, packed in at all angles, are structures still attached the leaves they came on, as well as bones of the victims of Redbelly Cal's hunts. This results in a dizzying array of random buildings sticking out at all angles in the nearly lightless interior.
These ghost towns are haunted by the spirits of the dead. When people are trapped or killed in the squirrel's raids, their bodies are lost to the maze of broken buildings and dead ends. With seemingly no way to escape, the victims waste away or are eaten by the beast, and their spirits become stuck in the nest.