The picture ? It's not a horsehead. is not a horsehead fish , ? It should be ?

Longhornfish of the family Labridae, genus Iniistius

Below is Iniistius baldwini

Distributed in the Pacific Ocean, including the waters of Vietnam, Japan, Taiwan, and the Hawaiian Islands. It mainly inhabits clean, clear lagoons with sandy mud bottoms or the periphery of reef edges; it is usually found in large groups, but occasionally as a lone wolf. During the day, it preys on shellfish attached to the seabed and small crustaceans climbing on rocks, and at night it burrows into the sand to rest. When frightened, it immediately burrows to the bottom of the sandy mud to hide.