A mysterious creature recently washed up on the shore of Lake Michigan, photos show, triggering speculation, fascination and the question, what the heck is it?

Robert Loerzel, a photographer and freelance journalist, came across the decomposing animal on Montrose Beach, in Illinois, he said in a tweet.

Whatever it was, it appears to have died quite some time ago. But what remained of it, the serpentine skeleton and scaly skin, provided plenty of fuel for people’s imaginations.

“I KNEW there were sea monsters in Lake Michigan,” a Twitter user commented on Loerzel’s post.

Well, it does look exactly like a dead version of the 1893 Lake Michigan Sea Serpent sketch: pic.twitter.com/kesk6CHyaR

— Adam Selzer | אדם (@adamselzer) May 1, 2022

“Scary looking,” wrote another.

“A sign of the apocalypse,” one comment read.

Looking for answers, Loerzel shared his photos on iNaturalist, a self-described “social network of naturalists, citizen scientists, and biologists.”

The consensus was that Loerzel’s mystery critter is a type of fish called a burbot.

IT'S A MERMAN! pic.twitter.com/qrC3lHPRD1

— Courtenay Elementary (@CourtenayTigers) May 1, 2022

Despite being one of Lake Michigan’s top predators, the burbot is seen as a somewhat obscure resident, the Milwaukee Journal Sentinel reported in 2019.

They can grow to around 60 pounds, but spend most of their lives out of sight, hanging at the bottom of the lake, where it’s deep and dark, the outlet reported.

While considered undesirable by many — a trash fish that’s ugly to boot — others see a “poor man’s lobster,” a fish that tastes significantly better than it looks, according to the Sentinel.

(editor：)