The octopuses of the genus Grimpoteuthis are also known as Dumbo octopuses from the ear-like fins protruding from the top of their head-like bodies, resembling the ears of Walt Disney's flying elephant Dumbo.
They are bathyal creatures, living at extreme depths of 3,000 to 4,000 metres (9,800 to 13,000 ft), with some living up to 7,000 metres (23,000 ft) below sea level, which is the deepest of any known octopus. They are some of the rarest of the Octopoda species. They can flush the transparent layer of their skin at will, and are pelagic animals, as with all other cirrate octopuses. The largest Dumbo octopus ever recorded was 6 feet (1.8 m) in length and weighed 13 pounds (5.9 kg), although the normal size for the various species is thought to be smaller.
They hover above the sea floor, searching for polychaetes, pelagic copepods, isopods, amphipods, and other crustaceans for food. The Dumbo octopus is strange in the way it consumes food in that it swallows its prey whole, which differs from any other kind of octopus. They move by pulsing their arms, shooting water through their funnel, by waving their ear-like fins, or any combination thereof. Males and females differ in their size and sucker patterns. Dissected females have yielded eggs during different stages of development, which has led to the conclusion that females lay eggs constantly, with no distinct breeding season. Male Dumbo octopuses possess an enlarged segment on one of their arms, similar to the hectocotylus arm of other cephalopods. It is likely that this modified arm transfers masses of spermatophores into the female during copulation, as occurs in other cephalopods.