Pagurus pollicaris is a hermit crab commonly found along the Atlantic coast of North America from New Brunswick to the Gulf of Mexico. It is known by a number of common names, including gray hermit crab, flat-clawed hermit crab, flatclaw hermit crab, shield hermit crab, thumb-clawed hermit crab, broad-clawed hermit crab, and warty hermit crab.
P. pollicaris inhabits the shells of shark eye snails and whelks. It grows to a length of 31 millimetres (1.2 in) and a width of 25 mm (1.0 in). The shell is often shared by the commensal zebra flatworm (Stylochus ellipticus).
The diet of the flat-clawed hermit crab comprises organic matter, algae, and sometimes other hermit crabs. Fish are the most important predators of this species.
