It sometimes seems to me that eating fellow vertebrates is a degree of cannibalism, for we do share very much with our fellow vertebrates in the way of anatomy and natural intelligence, and when it comes to dining on fellow mammals—all the more.

Cannibals? who is not a cannibal? I tell you it will be more tolerable for the Fejee that salted down a lean missionary in his cellar against a coming famine; it will be more tolerable for that provident Fejee, I say, in the day of judgment, than for thee, civilized and enlightened gourmand, who nailest geese to the ground and feastest on their bloated livers in thy paté-de-foie-gras.

Ishmael, Moby Dick

The consumption of alien beings such as octopi also seems a degree of cannibalism since they too share a degree of intelligence with us, though their intelligence is quite alien to ours.