Haliphron

The seven-arm octopus (Haliphron atlanticus), also known as the blob octopus or sometimes called septopus, is one of the two largest known species of octopus; the largest specimen ever discovered had an estimated total length of 3.5 m (11 ft) and mass of 75 kg (165 lb). The only other similarly large extant species is the giant Pacific octopus, Enteroctopus dofleini.

The genera Alloposina (Grimpe, 1922), Alloposus (Verrill, 1880) and Heptopus (Joubin, 1929) are junior synonyms of Haliphron, a monotypic genus in the monotypic family Alloposidae, part of the superfamily Argonautoidea in the suborder Incirrata of the order Octopoda.