octopus Octopus vulgaris and its relations, an edible mollusc whose consumption has been inhibited, except in the Mediterranean countries and the Orient, by what is considered to be its alarming or repugnant appearance (a view not shared by the Japanese, who regard it as an amiable creature, as explained under cephalopods); by its largely undeserved reputation as a peril to divers—it is known as devil-fish in the USA; by the need (notorious but in fact not always applicable) to tenderize the flesh before cooking; and perhaps also by the unresolved difficulty of deciding what its plural form should be (a difficulty which must have caused at least some people who would otherwise have bought two to ask for only one).