Hermit Rat

The Hermit Rat (official translation: Hermit-Dwellers) is a species of rodents that inhabits the city areas of the 6th layer of the Abyss.

Description
Their sharp teeth seem to help them shape the inside of their dwellings, which range from various ammonites to lost Delver helmets.

It is theorized that they use objects as dwellings in order to camouflage themselves from the various predators of the 6th layer.