Tetragonizus Billberg, 1833 Lactoria is a genus of marine ray-finned fishes belonging to the family Ostraciidae, the boxfishes.

[2] The 5th edition of Fishes of the World classifies this genus within the family Ostraciidae in the suborder Ostracioidea within the order Tetraodontiformes.

[3] Lactoria means a "milkcow", a reference to the large spines above the eyes resembling the horns of a cow.

[2] Lactoria cowfishes have thick, rectangular bodies that are largely enclosed in a carapace which is made up of thickened, hexagonal plate -like scales which are jointed to each other.

They have small mouths located at the front of the snout, with fleshy lips and a row of no more than 15 moderately sized conical teeth in each jaw.