The Origins of 5 Famous Sea Monsters and Water Legends

Mermaids, the Kraken, the Leviathan, disappearing ships, and disappearing sailors… tall tales of Sea Monsters, or legends with a grain of truth?

Dec 16, 2022By Nita Gleimius, BA Ancient Near Eastern Cultures & Biblical Archaeology

famous sea monster legends origins


Nessie, or the Loch Ness Monster, despite debunked sightings, faked photos, and negative scientific investigations, still has die-hard followers. Among other things, sea monsters like the Scandinavian Kraken and the Bible’s Leviathan have been discussed, explained, and written about as both real and mythical creatures.


The water sources of our planet above and below ground, in springs, rivers, oceans, lakes, and sinkholes have a myriad of myths and legends woven around them. These stories are not always about sea monsters or other hideous creatures beneath the surface. The mysterious depths of the oceans and lakes through which our sight cannot penetrate inspire our imaginations with feelings of wonder, awe, and curiosity – inspiring far-fetched beliefs.


1. The Kraken Sea Monster and Giant Squids

kraken sea monster
Kraken Sea Monster attacking a ship, via the BBC


The terrifying Kraken was first mentioned by a Norwegian king, Sverre Siggurdsson, in 1180 CE. Many tales of the Kraken surfaced subsequently in the accounts of seafarers and pirates across the oceans, although the creature seems to have been based in the seas around Norway and Iceland. It was described as a crablike sea monster with either tentacles or arms that could reach up to the topmasts of sailing ships, and its gigantic body was sometimes mistaken for an island.


This mythical sea monster aggressively attacked ships and either crushed them, capsized them, or pulled them down into the depths of the sea. Sailors were plucked from their ships during a voyage and eaten or just left to drown.

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Over time the Kraken took on a more squid or octopus-like appearance. In some descriptions this sea monster has ten arms and in others eight. In reality, both of these creatures have eight arms with suckers, and the squid has an additional two tentacles (appendages with suckers only at the end) which may account for the difference.


It is thought that the Norwegians saw bits of carcasses from dead specimens of these giant sea monsters washed up on their shores, and from there the legends spread. They were alternately seen as both good and bad — messages from God, or messages from the devil.


giant squid japan
Giant Squid, from Japan, 2015, via the New York Times


The famous author, Jules Verne, did not know when he wrote his science fiction novel Twenty Thousand Leagues Under the Sea that the giant squid portrayed in his famous novel was in fact a real sea monster! The reality of it was confirmed when Japanese scientists photographed a live specimen of this sea monster in 2004. They subsequently managed to capture one and bring it to the surface.


Scientists have since discovered many interesting facts about the giant squid. Like a living jet engine, this true sea monster propels itself forward by blasting sucked-in water out through a rear funnel. They have eight suckered arms and two tentacles. These longer tentacles are used to bring food into their parrot-like beaks.


The females can grow up to an enormous size of over fifty feet (over fifteen meters), and the males are just a little shorter at around thirty-two feet (over ten meters). Their eyes are up to ten inches (25.4 cm) in circumference, which allows them to see in the dark depths of the ocean where they live. One can imagine what a fearful sight such a sea monster would be for already superstitious sailors. And thus, legends of such creatures crushing flimsy wooden ships and feasting on sailors went from seaside taverns to urban communities — growing in size as they spread!


2. The Deadly Allure of Mermaids

mermaid painting sea monster
The Mermaid, by John William Waterhouse, 1900, via the Royal Academy


“Ich Weiss nicht was soll es bedeuten,

Das ich so traurig bin;

Ein Märchen aus alten Zeiten,

Das kommt mir nicht aus dem Sinn”.


Thus starts the German poem Die Lorelei by Heinrich Heine. He muses that he does not understand why the old tale keeps circling in his mind. The tale of a beautiful maiden on a rock in the Rheine River, combing her golden hair with a golden comb and luring sailors with her enticing and irresistible song to wreck their ships on the rocks. Although Lorelei is not portrayed with a fishtail nor shown living in an ocean, her story describes the quintessential mermaid.


The story reminds us of Odysseus and the sirens, and other similar folktales in many cultures, that talk of mermaids luring sailors to their deaths, all across the world. Not a typical sea monster in looks, the mermaid is a sea monster in behavior. Through folktales, plays, children’s story books, and Hollywood movies, mermaids have played on our imaginations even in this century, as a water spirit, a water nymph, a sea monster, or a malicious water god — with a human upper body and a fishy tail.


One famous example comes from an Animal Planet documentary from 2012/13 in which producers claimed to have found proof of a real mermaid. It was so convincing that the National Oceanic and Atmospheric Administration in the USA felt obliged to issue an official statement denying the existence of merfolk.


A manatee, via National Geographic


Because of the myth of merpeople (mostly mermaids) is so widespread, people have tried to come up with several explanations for these visions. The most sensible so far is that a drunken (or not!) sailor or beachcomber might easily mistake a manatee surfing the waves or catching its breath while rising from the water for a fish-tailed human. Manatees have to come up for air around every twenty minutes or less. Most of us, though, accept merfolk as just a jolly good tale.


3. Greek Mythology’s Sea Monster Scylla

scylla pottery sea monster
The Scylla sea monster, red figure bell-crater, c 450 – 425 BCE, via


The Scylla was not always a sea monster. She was a water nymph and the daughter of Ceto — the ultimate sea monster — and Porchys in Greek mythology. Odysseus, the legendary hero who instigated the Greek victory through his clever plan involving the Trojan horse after ten years of battle in the Trojan war, had to get past this giant creature on his way home to Ithaca. Homer uses the sea monster Scylla and her equally evil neighbor, Charybdis, to illustrate the dilemma of choosing the lesser of two evils.


Later Roman authors of Greek myths such as Ovid, describe Scylla as a beautiful woman who had the misfortune of attracting the attention of a sea god called Glaucus. Glaucus asked a Greek witch, Circe for a love potion to get Scylla to fall in love with him. In revenge Circe, who was herself in love with Glaucus, turned Scylla into a hideous sea monster. As with all Greek myths, there are several versions of Scylla’s story, and in some her parents were Titans, and Glaucus was a fisherman. In still other versions the jealous competitor is none other than the wife of Poseidon, the Greek god of the sea.


4. The Flying Dutchman

flying dutchman
The Flying Dutchman, by Charles Temple Dix, 19th century, via Culturetrip


Sailors of sailing ships were rather superstitious according to legend, and always on the lookout for sea monsters. The famous Hunt-Lennox Globe (c 1510 CE) quaintly identifies unknown seas with the words “… here be dragons.” On the other hand, they must have been very brave to sail in their frail vessels on the vast open and unexplored oceans, often for lengthy periods without sight of land. A little rum would often give them courage through the lonely hours of the night and could easily interfere with sight and logic.


The legend of The Flying Dutchman is the story of a ghostship under full sail racing through a raging storm. The story goes that a captain of a trade ship of the Dutch East India Company was returning from a successful trading mission to India. A fearful storm crossed his path as he was rounding the Cape of Good Hope. His sailors begged him to seek shelter by returning to port, but he was in a hurry to get back to Amsterdam and earn more money.


He blasphemed and swore that he would finish the journey even if it took until Doomsday. The devil, or an angel, heard his words and challenged him to try, or else sail the oceans forever. The ship was lost in the storm with the captain and his crew condemned to sail the oceans for eternity. Like most legends, there are a few different details to the story in various versions of the legend.


Sailors believed that sightings of this ghostship would often lead to impending disaster, and sailors were petrified of seeing it until as late as the previous century. Modern explanations of the sightings include ghostly reflections known as fata morgana (mirages) in the right atmospheric conditions.


5. The Leviathan 

leviathan sea monster
The Destruction of Leviathan, by Gustave Dore, 1865, via Wikimedia Commons


Most people know of the leviathan from several biblical references. It was known as a gigantic and horrific serpent-like sea monster, a representative of evil in oral Hebrew literature and older middle eastern mythology.


According to the Book of Enoch (part of the biblical Apocrypha), the leviathan was a female sea monster consigned to the oceans, while her male counterpart, the behemoth, was assigned to the wilderness east of Eden. In the Book of Psalms from the Bible, the leviathan is a sea monster with multiple heads.


In one version of the Leviathan myth, the creature was an angel serving under the archangel Uriel. When Satan rebelled and challenged authority in heaven, Leviathan joined him and was thus banished from heaven with Satan. He changed into a hideous sea monster whose enormous gaping mouth can serve as a gateway to hell.


Real Sea Monsters

portuguese man of war
A Portuguese Man o’ War, by Mike Theiss, via National Geographic


Sea monsters may not always fit the concept of our preconceived ideas of enormous and ugly creatures, but like the beautiful mermaids above, their deeds can be deadly. The Portuguese-man-of-war may look harmless and pretty, but the mere touch of a tentacle, similar to some types of the box jellyfish in the Pacific Ocean and Australian coastal waters, can cause almost instant paralysis of the muscles, including the heart — leading to an almost instant death-knell.


Sea monsters in the shape of snakes or serpents are also alive and well, although not in the enormous sizes of folklore. One species of shark, the frilled shark, looks like the sea serpent of legends with its frilled neck and rather lizard-like head. Sea serpents are not all deadly or poisonous, but one should not test them.


Among horrific-looking deep sea creatures, are the (although not gigantic) fangtooth and viperfish. The alien monsters in sci-fi movies are good look-alikes for these real sea monsters. We are not threatened by these creatures as they live in the very deep parts of the ocean where a human would be long dead if they made it that far down.


meglodon shark
Megalodon shark at the AMNH exhibition, by Dr. Finnin, via Forbes


Fossils of a terrifying extinct sea monster with powerful jaws, resembling a serpent cross crocodile, was discovered in 2009 with a head measuring over six feet (almost two meters). It belonged to the dinosaur era and is called a pliosaurus. Other extinct sea monster species that can be seen in natural history museums include the giant shark the Megalodon among others.


Sperm whales have also become legendary through the famous Herman Melville classic, Moby Dick. Sperm whales are the largest mammals with teeth in our oceans today, but humans are not part of their diet or plans for revenge despite Moby Dick and Captain Ahab’s obsession!


And then there is the shark from Jaws! This monster of the oceans is as real as can be, albeit not the same size as in the movie or with the same intentions. Although it is not as vicious or large as the movie monster, the Great White shark is a devourer of anything that moves or shines, and a real danger to swimmers and surfers.


Sea Monsters Are Real — and Some Are Cute

sea dragon sea monster
A Sea Dragon sea slug, photo by S. Rohrlach, via


Every ancient culture has its own sea monsters living beneath the surface of our vast oceans. Even landlocked countries created myths and stories of sea monster-like creatures around waterholes, rivers, underground water, lakes, and springs. Some contemporary cultures still believe in water spirits — good and bad — that have to be placated in some way to avoid disasters.


The mysterious depths of our vast oceans harbor exciting and scary secrets and wonders and because we cannot see through the water — well, most of it, anyway — our imaginations can conjure up fascinating illusions. No wonder many tall tales are spun around the waters of our unique blue planet.


More than seventy percent of our earth is underwater, the largest mountain range is in the depths of the Atlantic Ocean, and the deepest place on earth — as far as we know — is the Marianna trench in the Pacific at 7 miles (11.27 km). Scientists and explorers have only been able to examine the deep with real effectiveness through the use of modern equipment for less than fifty years. What wonderful treasures and confirmation of legends may yet be waiting for humankind!

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By Nita GleimiusBA Ancient Near Eastern Cultures & Biblical ArchaeologyNita holds a BA degree in Ancient Near Eastern Cultures and Biblical Archaeology. Her subjects included Ancient (Classical) History and Ancient South Eastern Asia. She has written books, articles, and more as a ghostwriter. Nita has wandered around many ancient sites and museums in several countries. She is an avid reader of fiction and non-fiction alike, and retains a keen interest in reading, researching, and keeping up to date with ancient and prehistoric discoveries across many parts of the world.