Enchoteuthis

While rather fragmentary, one thing is known for certain about Enchoteuthis: it was big. With a full body measuring somewhere in the 3 - 4 meter range, Enchoteuthis was among the largest cephalopods of all time and the largest octopus relative prior to the description of the titanic Nanaimoteuthis. Not much is known about the life appearance or ecology of this beast, but if it's anything like modern octopus, it would have been a fierce and cunning predator.