A random post from Thailand on social media, showing a whale treading water with its mouth agape trapping a shoal of anchovies, went viral in 2021 – and reminded those familiar with the Norse sagas of a mythical sea creature: hafgufa.

Perhaps something like this existed after all. 

Described in an Icelandic story from 1200 known as Konungs skuggsjá, this maritime being was said to give off a particular smell before catching fish in its mouth. 

With no evidence of any such behavior, the tale was dismissed as just that, a tale. 

Truth or legend?

But then, as more people studied the particular and peculiar feeding technique of humpbacks and Bryde's whales, a sub-group of baleen whales, it slowly dawned on experts that perhaps there was some truth in these legends after all. 

One such specialist is Dr. Erin Sebo, attached to Flinders University in Adelaide, Australia. 

Dr. Sebo talks to The Viking Herald about how her niche area of expertise sheds light on this strange natural phenomenon and its connection to a Scandinavian legend more than 1,000 years ago.

"I'm a specialist in medieval literature and historical linguistics," began Dr. Sebo. "I've done a lot of interdisciplinary work with archaeologists and geophysicists looking for ways that literature and linguistics can be used as a source of evidence. Historically, literature has not been used well as evidence, but with the right methodologies, it can be very reliable."

"For this project, my job was to find texts that described this kind of behavior, to contextualize medieval descriptions of animals and animal behavior (which are very different from the way we describe them!), and to determine which texts showed direct community knowledge of this type of whale behavior and which relied on copying information from older sources."

A Bryde's whale feeding on sardines.Photo: wildestanimal / Shutterstock

What could it be?

"In medieval accounts, the thing that all the texts stress is the massive size of the hafgufa. In many texts, it is actually mistaken for an island. It sits still in the water, and fish jump into its mouth. The 13th-century Konungs skuggsjá ('The King's Mirror') actually expresses concerns about biodiversity because of the amount of fish the hafgufa can consume! Perhaps because of its massive size, it is confused with the Kraken by early modern writers."

Until now, historians attempted have struggled to compare this particular area of Norse mythology to the natural world. 

Dr. Sebo suggests a few of the more outlandish proposals: "There have been some fabulous theories! One suggested hafgufa sightings were the result of a specific kind of optical phenomenon where strong, non-uniform atmospheric refraction associated with storms causes visual distortions. Another proposed that it might be the result of underwater volcanoes. Because of the confusion with the Kraken stories, many have suggested that the hafgufa might be a giant squid".

The Thai viral posting not only amused many watching on their mobiles but had Norse specialists reaching into the sagas: "My colleague, Dr. John McCarthy, is the one who first saw the post, and he instantly thought of the hafgufa legends. He called me and asked what texts it appears in and also if I could check the wording in the original Latin and Old Norse so that we could be sure that nothing was being lost in translation". 

The jury is out, however, on whether this confirmation from the natural world alters our understanding of the hafgufa myth or not: "In a way, it doesn't! The earliest Scandinavian texts speak about this animal, not as something magical, but as one of the many amazing creatures in the ocean – and they were right! 

"I think it should encourage us to see the ways in which medieval people had specialist knowledge. They don't have our scientific frameworks for understanding the world, which means that there are misunderstandings. 

"Nevertheless, they lived very closely engaged with the natural world, and their survival depended on working with it. We shouldn't be too surprised that their observations are intelligent, drawing sensible conclusions based on the evidence they had in front of them".

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