The Internet has been left baffled after a bizarre creature washed up on a Californian beach. Reddit user xxviiparadise found the animal on the shore of the Leo Carillo Beach in Malibu. The sea creature appears to be fairly smooth, and looks like an oversized and discolored mussel.
The photographer posted his find to Reddit, with the concise caption: "Anyone have any idea what this is?!"
According to xxviiparadise, whatever it was was roughly the same weight as a new-born baby.
"It weighed around 7 pounds and if I had to guess about 5 inches wide," he wrote to one curious Redditor.
Other users speculated that it was some kind of gigantic sea snail, and asked for more angles of the creature. xxviiparadise provided that, but it didn't really clear anything up, and just revealed more strange parts to the creature that need even more explaining.
Another Redditor speculated that it "looks like whatever it is it lives inside the seashell".
When the images were posted to the marine biology subreddit, the answers started to get a lot more scientific, and one Redditor thinks they may have solved the mystery. After asking whether the creature washed up in Southern California, the Redditor became pretty sure of what it was.
"I'd say that, my friend, is a long-dead sea hare," PacificKestral said. "As a marine biologist, I've seen plenty. They start to look all sorts of weird the longer they've been dead, but that big muscular foot running along the side there is pretty characteristic."
Whilst it's not 100 percent clear that it is a sea hare that was washed up and found, it does seem like a pretty clear candidate. The Californian sea hare is a species of sea slug that is common off the west coast of the US and northern Mexico.
They can grow to be pretty massive as well, and it appears that this one was actually just a small one. The maximum recorded length of a Californian sea hare is 75 centimeters (30 inches), and adults of the species can weigh up to 15 pounds (7 kilograms).