The Great Land Crab, a/k/a Duppy, (Cardisoma guanhumi) in the mangrove lagoon swamps of Mandahl Bay, St. Thomas, Virgin Islands. Duppies are the main crab used for the popular West Indian dish, Crabs and Rice. It is the largest of the land-dwelling crabs on St. Thomas and known for its abundant and succulant meat. These crabs are vegetarians, feasting on fruits and leaves. While they are tasty to eat, amateur crabbers should use caution. The crabs like to eat the Manchineel Tree fruit which is poisonous to humans. Eating a crab that has fed on Manchineel fruit can lead to severe stomach problems, including ulcerous lesions. Crabs need to be properly purged before being consumed.