Inimicus didactylus, also known as Demon Stinger or Devil Stinger, is a member of the Inimicus genus of venomous fishes, closely related to the true stonefishes. It can reach a body length of 25 cm (10 in) and is irregularly surfaced with spines and a knobby appearance. The fish has venomous spines to ward off enemies. The fish are nocturnal, and often dig themselves partially into the sandy seabed during the day. The body is red or sandy yellow and well camouflaged on sandy and coral seabeds.