Lasiognathus saccostoma is a species of marine ray-finned fish belonging to the family Thaumatichthyidae, the wolftrap anglers.

Lasiognathus saccostoma was first formally described in 1925 by the English ichthyologist Charles Tate Regan with its type locality given as the Caribbean Sea, approximately 98 km (61 mi) northwest of Negril, Jamaica at 18°50'N, 79°07'W, from a depth of around 2,000 m (6,600 ft).

[3] The genus Lasiognathus is classified by the 5th edition of Fishes of the World in the family Thaumatichthyidae within the suborder Ceratioidei of the anglerfish order Lophiiformes.

The specific name saccostoma, combines sakkos, which means "bag", "pouch" or "pocket", with stoma, meaning "mouth", a reference to the premaxillaries having a wide membrane which connectes them to the head, this makes a membranous pouch, the "trap" of wolftrap, in which the fish holds its prey before swallowing it.

The appendage on the tip has a cylindrical stalk with thin filaments emerging from the front base of the black hooks on the esca.