Tales of giant squid and outsized octopuses have haunted mankind since ancient times. The fact that enormous beasts lurk beneath the ocean waves is no secret, and the discovery of a creature with tentacles the length of a football field has inspired primordial nightmares in the most placid humans. From the kraken of European lore to the Ainu people’s Akkorokamui, mythology is full of ravenous mollusks who prowl the ocean, sinking ships and claiming human pray. Never mind that actual squids and octopuses, even the so-called “colossal” variety, simply aren’t big enough to devour a human, let alone sink a large boat; nor that giant squids rarely if ever emerge from the deep ocean, with the first video of a live creature not captured until 2001.

We needn’t go back to antiquity to find such stories, either. There are numerous claimed stories of giant squids attacking boats and even devouring humans. The French warship Ville de Paris was reportedly pulled under the sea by a horde of ravenous squids during the American Revolution (other sources suggest it was a hurricane). A century later, a trio of sailors near St. Helena were reportedly dragged from their boat and eaten by a tentacled hellbeast. But these molluscan misadventures are genuinely dubious, based on secondhand accounts and relegated to books on cryptozoology rather than serious scientific works. Only one case has received sustained attention outside of the Bernard Heuvelmans and his ilk, and even this story becomes dubious the longer one examines it.

On March 25, 1941, the SS Britannia (an ocean liner converted to a troop ship) was en route to Bombay with a complement of soldiers when it was intercepted by the German surface raider Thor off the coast of Sierra Leone. Armed with a single protective cannon, the Britannia engaged the Thor in an uneven battle which lasted an hour. Eventually, German artillery took its toll and the vessel was mortally wounded. The German captain ceased firing long enough to allow the passengers and crew to abandon ship; however, he did not move in to rescue the survivors due to a warning of British warships rushing to the area.

Unfortunately for the Britannia’s crew, these warnings were incorrect; they were left adrift in overcrowded lifeboats with little food or water. One intrepid lifeboat crew traveled the width of the Atlantic Ocean, reaching Brazil twenty-three days after the sinking. The others remained adrift in the Atlantic for five days, with many perishing from exposure or drowning; ultimately, 249 of its passengers and crew died before several Spanish vessels rescued the 300-odd survivors.

The British press covered the sinking, based on eyewitness testimony, with an eye to the treachery of the German captain and the hardships faced by the men. The Illustrated London News ran a feature on November 1, 1941 entitled “The Most Macabre Incident of the War At Sea; Marine Monsters Devour Men Adrift on a Raft.” It featured imaginative drawings of the harried sailors menaced by a school of sharks and, improbably, a giant manta ray swooping in for the kill. The story cited one survivor, Lieutenant R.E. Cox, as the source for its tale, which however embellished certainly raises the hackles of anyone reading it:

On the tiny raft harbouring twelve men there was not room for all, so they had to take turns in the water, leaning their bodies on the fragile raft, which was always eighteen inches under water. Mr. Cox, while hanging in the water, was stung on the leg, hand, mouth and head by a “Portuguese man-of-war,” a poisonous jellyfish, which caused excruciating pain. The sun, blazing hot, reflected on the sea like a magnifying-glass, blistered the skin and caused fearful thirst. A naval officer was the first to go raving mad. His body was thrown overboard and the following morning the others found themselves surrounded by hundreds of sharks, whose fins protruded everywhere. Others lost their reason, and frequently the raft capsized when men became utterly insane – one of whom violently attacked Mr. Cox – until on the fifth day an Indian servant first had his legs bitten off by a shark and then, to add to the horror, a huge manta, or devil-fish, seized his body, folded its great fins round the victim, and devoured him.

For decades, Lieutenant Cox remained the principal teller of the Britannia’s sorry fate. His story, though likely embellished for the delectation of wartime readers, seems plausible aside from the man-eating manta ray (mantas are tiny-mouthed filter feeders incapable of “devouring” anything larger than shrimp). Over time, however, his story evolved into a harrowing tale of cannibal krakens.

In 1956, Cox spoke with naturalist Frank W. Lane, who was researching stories of cephalopod attacks on human beings. In his resulting book, Kingdom of the Octopus (long after a standard reference work on cephalopod behavior), Lane cited Cox’s tale of terror: rather than sharks and “huge mantas,” his raftmates were victimized by a giant squid. The giant squid, so fearsome that it scared off the prowling sharks, flailed at the raft with its tentacles, grabbing Cox and a number of others. The Indian servant who was bitten by a shark in the original story was now “hugged like a bear” by the malevolent mollusk, who pulled the victim into its gaping maw. As proof, Cox showed Lane circular scars on his legs from the attack, which a doctor claimed could only have come from a squid or octopus.

Lane’s citation of this improbable incident – much embellished beyond the already harrowing tale of shark attacks and stinging jellyfish – caused it to be repeated, for decades, in works on marine biology (not to mention books on cryptozoology, documentaries on Unsolved Mysteries and other, less scrupulous accounts). One popular science writer touted it as “the only verified case of a giant squid attacking humans,” substantiating the old myth of ship-sinking krakens. Never mind that even the largest squid (600 pound specimens have been recorded) couldn’t pop humans into its mouth like chicken nuggets; the absurdity of the tale doesn’t prevent its resonance with centuries of tentacle lore, giving a modern gloss to one of mankind’s oldest myths.

There is one possibility that doesn’t strain credibility. The Humboldt Squid, nicknamed the jumbo squid, is certainly capable of aggressive behavior towards humans. There are numerous cases of scuba divers and fishermen coming into contact with these squids, who will sometimes grab or even drag down divers; some particularly aggressive species have been known to bite divers or squirt them with ink. Marine biologists believe that this is territorial behavior rather than malicious aggression, or else the natural curiosity of a cephalopod faced with an intruder. And the largest recorded specimens are “only” 4 ft. 11 inches long – still intimidating, but hardly the length or size of their giant, let alone colossal cousins.

It’s not beyond imagining that Lieutenant Cox was grabbed by a curious squid in the open ocean, resulting in the scars he showed to doctors decades later, without any malicious intent on the creature’s part. It’s more likely though that his original story of being stung by a man-o-war while suffering thirst and fear-wracked delirium led him to embellish the story for reporters, and embellish it a second time a decade later to a credulous science writer who saw nothing strange about a beaked crustacean-eater scarfing down humans nearly the same size. It’s least likely that the Kraken, much as it appeals to readers, prowls the briny deep in search of human prey.