E. zealandicus is a large octopus, reaching a total length of at least 1.4 metres (4 ft 7 in),[1] though few whole samples have been collected and this is only a guide.

Samples have been collected along the east coast of the south island, Chatham Rise, Campbell Plateau, Stewart, Auckland and Antipodes Islands; and from the surface down to 530 metres (1,740 ft) depth.

[1] There is an absence of published information about the preferred habitat or diet of this species.

Enteroctopus zealandicus is one of the most important prey of New Zealand sea lions at the Auckland Islands and Campbell Island, in the New Zealand Subantarctic.

[2][3][4] It has also been identified from beaks found in the gut of beached whales.