hammerhead, hammerhead shark
['chiton, coat-of-mail shell, sea cradle, polyplacophore', 'amphibian, amphibious vehicle', "plunger, plumber's helper", 'nematode, nematode worm, roundworm', 'hog, pig, grunter, squealer, Sus scrofa', 'proboscis monkey, Nasalis larvatus', 'mud turtle']