The titan triggerfish, (Balistoides viridescens) is found in lagoons and at reefs to depths of 50 m (160 ft) in most of the Indo-Pacific. With a length of up to 75 centimetres (30 in), this triggerfish is diurnal, solitary and territorial. It feeds on sea urchins, molluscs, crustaceans, tube worms and coral. It often feeds by turning over rocks, stirring up sand and biting off pieces of branching coral. Look at those teeth!!!
The titan triggerfish will not always bite, but can swim at snorkellers and divers escorting them out of their territory.