3 Biggest Crab Species🦀 | All About Animals The three largest crab species are: Japanese Spider Crab – the largest, with a leg span up to 12 feet and weighing up to 40 pounds. Tasmanian Giant Crab – has a carapace up to 18 inches wide and can weigh over 30 pounds. Coconut Crab – the largest land crab, with a 3-foot leg span and weighing up to 9 pounds. #crab #japanesespidercrab #tasmaniangiantcrab #coconutcrab #seaanimals | All About Animals