octopus octopus vulgaris, a soft-bodied, eight-armed mollusc grouped within the class cephalopoda with squids, cuttlefish

abyss algae and anemone animal aquarium aquatic arm beak cephalopod cephalopoda class coral creature cuttlefish display eightarmed fish fishtank freshwater glass grouped hectocotylus life marine mollusc mollusk monster museum mythology nautiloid nautiloids ocean ocelli octopi octopus octopuses pacific plant reef saltwater sea seabed seawater siphon softbodied squid squids sucker swim swimming tank tentacle transparent underwater vivarium vulgaris water within