The posterior portion of the shell has broad extensions with several blunt teeth on the margin, and these largely conceal the walking legs.

The carapace and the exposed parts of the chelae (pincers) are a mottled greyish-brown colour, and are covered with small raised tubercles of various sizes, making the crabs well-camouflaged when semi-submerged in the sand.

The chelae are large and powerful, and specially adapted to the crab's feeding behaviour, the crushing and eating of molluscs.

[2][4] Calappa hepatica is found in the tropical and subtropical Indo-Pacific region, its range extending from the Red Sea to Hawaii, French Polynesia, Cocos Island and northern Australia.

[5] During the day, Calappa hepatica remains buried in sand with only the area round the eyes protruding.