A cousin to the cuirass crabs of the forest, the cuirass mud crab is a vital consumer in the swamp ecosystem — preying on anything from algae and other small invertebrates to mollusks and small fish.

Though cuirass crabs are known for their hard shell, which are occasionally used by the Na’vi for an organic, renewable armor, they are prey to the rivernox and neoteni centipedes and gather together in colonies on tree branches and trunks for protection.