E. magnificus bears the distinctive characteristics of the genus Enteroctopus, including longitudinal folds on the body and large, paddle-like papillae. E. magnificus is a large octopus, reaching total lengths of up to 1.8 m and a mass of 11.4 kg.
Like many octopuses, E. magnificus is a generalist predator. The chief food source for this octopus is the deep-sea portunid crab Bathynectes piperitus. Other major prey items include the Cape hagfish (Myxine capensis ), the crab species Pontophilus gracilis, and hermit crabs in the genus Parapagurus.