Cardisoma crassum

Cardisoma crassum, known as the mouthless crab, is a species of terrestrial crab found in the coastal tropical eastern Pacific from Baja California to Peru. It has a purplish-blue shell, red legs and white main pincer. Cardisoma crassum is common among mangrove roots, where it builds its burrow. It also occasionally occurs on the driest part of the channel banks and flats".