They are human-sized crustaceanoids resembling a flat pillbug with countless tendril-like legs. They also have a pair of huge eyes (presumably to help them find their way in the dark nests) and a narrow, hollow snout from which they shoot blasts of venom which apparently takes the form of a bioluminescent liquid. They are rendered helpless if turned backs on the ground. The Larvae Guns' true nature remains unknown, as they might represent a distinct life stage or caste of the Zarbi, or a different species altogether which lives in symbiosis with them.