Claw

A claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). A true claw is made of a hard protein called keratin.

Similar appendages that are flat and do not come to a sharp point are called nails instead. Claw-like projections that do not form at the end of digits but spring from other parts of the foot are properly named spurs.