The smooth trunkfish was first formally described as Ostracion triqueter in 1758 by Carl Linnaeus in the 10th edition of Systema Naturae with its type locality given as "India", in error for the Western Atlantic.

[5] The smooth trunkfish has an angular body sheathed in plate-like scales, growing to a maximum length of 47 centimetres (19 in), though 20 cm (8 in) is a more normal size.

The general background colour is dark with a pattern of small white spots, often in hexagonal groups giving a honeycomb-like appearance in the middle area of the body.

[7] The smooth trunkfish is found down to a depth of about 50 m (164 ft) on coral reefs and over sandy seabeds in the Caribbean Sea, Gulf of Mexico and the western Atlantic Ocean.

It uses its protuberant lips to expel a jet of water which disturbs the sandy seabed and reveals any shallowly buried benthic invertebrates.