Hermit Rat

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

Description
Hermit Rats are, in general, not suspicious of others and very curious in nature, but might bite if push comes to shove.

Their teeth have a unique structure and their bite causes considerable pain, the wounds inflicted by it are difficult to heal. Their sharp teeth also 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.

Trivia

 * Irumyuui's Children bear some resemblance to the Hermit Rat.