Features coconut crab. The coconut crab, Birgus latro, is a species of terrestrial hermit crab, also known as the robber crab or palm thief. It is the largest land-living arthropod in the world, with a weight of up to 4.1 kg (9.0 lb). It can grow to up to 1 m (3 ft 3 in). It is found on islands across the Indian Ocean and parts of the Pacific Ocean mirroring the distribution of the coconut palm.