Abyscidis

Abyscidis were dog-sized crustaceans that lived in the shadow of the larger flesh eaters of the dark. Primarily scavengers, they were unparticular feeders, taking any organic matter they could scavenge, dead or dying. The chunky invertebrates clustered in loose colonies at the base of a pit or in deep caves. The nymphs, hatching in large numbers, used the rivers of organic slop to migrate around their dark domain, locating an unclaimed section of cave or chasm shoreline to mature in and establish a new colony.

Monster crabs from King Kong is a 1- 2 feet long smaller relative of the mighty Deplectors that clung to the walls of the abyssal Chasms.