hammerhead, hammerhead shark
['horned viper, cerastes, sand viper, horned asp, Cerastes cornutus', 'ringneck snake, ring-necked snake, ring snake', 'quill, quill pen', 'green snake, grass snake', 'vine snake', 'breakwater, groin, groyne, mole, bulwark, seawall, jetty', 'bow']