Vilstrak have a rocky hide that allows them to blend well with their subterranean habitat, using an innate ability to merge with the rocks. These monsters are 75% undetectable until closer than 20-ft, at which point they often move to attack with their massive fists.

These creatures tend to lair in hollows of rock and earth. These lairs are difficult to readily access by any being unable to pass through earth and stone, though with some time and effort the opening can be widened enough to allow entry and access to the treasure, gleaned from the vilstrak’s victims, stored therein.

Vilstrak appear as a 6-ft tall cross between a human and a bug and has a hide with the consistency of heavy rock. Its forearms are half again longer than that of a human and much more massive, ending in two heavy fists.