My father inlaw sent me these photos. They are called Coconut Crabs. I can't imagine coming across one of these in the dark!!!! Coconut Crab (Birgus latro) is the largest terrestrial arthropod in the world. It is known for its ability to crack coconuts with its strong pincers in order to eat the contents. It is sometimes called the robber crab because some coconut crabs are rumored to steal shiny items such as pots and silverware from houses and tents.