On a post in another subreddit, I saw this comment (provided below) about the origins of the Kraken and that it started as a whale. What are some facts about the origins of the kraken and, more importantly, what are some articles that I could read about the kraken? “The idea that the kraken is/was an enormous octopus is a rather late development of the story. In the earliest versions, descriptions included traits that are associated with whales rather than with squid, and it was often described as a giant crab so enormous as to appear to be an island. Given the limited geographical range assigned to kraken by pre-1800s tales, waters off Norway and Iceland/Greeland and the bubbling, spouting, dangerous new currents and high waves associated with its rise from the bottom, it is more likely to be a response to undersea volcanism in the Iceland region. If this is the case, then the kraken still lurks off the coasts of Iceland, and was last seen to rise in 1973.”
The story is that there's not much of a story here. The origin of "The Kraken" is the poem by Lord Tennyson, who popularized the Krake (CRAW-keh, definite form Kraken) that the Danish bishop in Norway Erik Pontoppidan (jr) wrote about in his 1753 book Det første Forsøg paa Norges naturlige Historie (A first attempt at a natural history of Norway). That reference was picked up by Melville in Moby Dick and then into other Anglo-American pop culture in the 20th century. (no doubt the name of the poem contributing to the grammatically bad name 'The Kraken' catching on)
Pontoppidan's account is not a documentation of the folklore as much as an attempt at synthesizing various bits of folklore into a single creature, which he thinks is a polyp (octopus) or starfish. It's clear at the outset he's drawing on more than one account when he explains Kraken is also known as Kraxen, Krabben (the crab), Horven (the harrow, as in the farming implement), Søe-Horven (the sea-harrow) and Anker-Trold (anchor-troll). Later he also mentions names like Søe-Trold (sea-troll).
'Krake' is an alternate/dialectal term for octopus in Norwegian (and the common word in German) for, but it is a cognate of 'crooked' and can really mean any old or sickly animal. It's unclear if Pontoppidan preferred this term above the others he enumerates because it was the most common one or because it fit better with his octopus theory.
Pontoppidan references a number of different stories. The main one is that the Krake supposedly lies at the bottom, and his presence lures a lot of fish, so when fishermen find the depth to be far lower than expected and lots of fish, they know Kraken is there. But if the depth soundings start getting smaller, they know Kraken is rising to the surface and have to row out of there quickly. He relays there are no accounts of the Krake destroying ships or killing people though.
Other minor accounts are such as people thinking medusa-heads (i.e. jellyfish) are baby kraker. A dead krake supposedly washed ashore in Alstahaug in 1680 and stank greatly, and is described Pontoppidan by as having long arms, or antennae. He also references all sorts of reports of disappearing islands he's dismissive of Olaus Magnus (who he quotes) who wrote in the 16th century about Scandinavian sailors mistaking whales for islands, but thinks the islands may have been the Krake. He also attributes to it the mirage island of 'Gumars-øre' (sic; actually Gunnarsöre) between Sweden and Finland which had been put on Andreas Bureus 1626 map Orbis arctoi nova et accurata delineatio and later described by Clas Gripenhielm. Floating/disappearing islands in general are the Krake as far as Pontoppidan was concerned.
In short though, there's no reference to Kraken before Pontoppidan. It's not possible to say how widespread that particular name was or what things were specifically attributed to Kraken , as opposed to the other sea monsters like Søe-Trolden which Pontoppidan equates with Kraken. It's clear he believes in Kraken himself despite not seeing it, but you can't say how he adapted or presented the folklore to support his view. For all we know, Pontoppidan could've coined the term himself. All later references seem to derive from his account and there are no earlier ones. (even a Scandinavian 18th century mention, like Min Son på Galejan attributes what it knows the beast to Pontippidan, despite the book being written by a Swedish ship's priest who'd no doubt heard a fair share of folklore)
There are earlier records of sea-monster folklore of course. But connecting those with Kraken is to project folklore significance onto the creature just because of its present day pop-culture status. Ignoring Tennyson, Melville, and Clash of the Titans, there's not a whole lot in Pontippidan's account that makes it that much more interesting than other sea-monster stories, even other Scandinavian ones (like the aforementioned Olaus Magnus' ones).