monster

The Hafgufa is a giant fish or whale said in Old Norse writings to roam the seas.

In the Konungs Skuggsjá, a book of tactics and morality written by King Håkon Håkonsson for his young son, the king is loath to describe the creature—for no one, he says, will believe him without seeing it first with his own two eyes. As for him, he fears it, “for it is a massive fish, that looks more like an island than a living thing.”