If Scotland's Loch Ness monster has a cousin, it would be Storsjöodjuret, a creature up to 42 feet long that some believe is trapped in Lake Storsjön in Sweden.

Loch Ness monster's Swedish cousin Storsjöodjuret? (Andreas Eriksson/Wikimedia Commons)

Stories of such a monster living in Lake Storsjön have been around for centuries, the website Mysterious Universe reported, but many say stories of Storsjöodjuret are nothing more than passed-down folklore with no physical evidence to support the monster’s existence.

An undated article for Strangemag.com questioned if Storsjöodjuret was a relative of the Loch Ness Monster, saying the monster may have become trapped in the Swedish lake during the Ice Age some 15,000 years ago, and noting that creatures such as the Loch Ness Monster and Storsjöodjuret are not unique, with reports of similar sightings of creatures in lakes in Ireland, Denmark, Finland, Italy, Norway, and Wales.

There are no clear pictures of the reported Lake Storsjön monster, Strangemag.com said, but it has been described as a wormlike creature with recognizable ears ranging in size from 10 to 42 feet in length.

The Society for Investigating the Great Lake collected some 400 reports of the Sweden lake monster since the 1800s, Strangemag.com said.

"Fisheries officer Ragnar Björks, 73, was out checking fishing permits on Sweden's Lake Storsjön when he had the fright of his life," Strangemag.com said about one man's encounter with Storsjöodjuret, which was also undated. "From the placid waters a huge tail suddenly broke the surface near Björk's 12 foot row boat.”

"The colossal creature attached to the tail appeared to be 18 feet long, grey-brown on top with a yellow underbelly. When Björks was alongside the monster, he struck at it with his oar, hitting it on the back. Angered, the creature slapped the water with its tail and the rowboat was thrown nine to twelve feet into the air," the Strangemag.com entry said.