Internet users have been left puzzled after a bizarre sea creature washed up on a Californian beach.
The strange creature appeared to have no eyes or a mouth and two large lumps sitcking out of one end of its body.
Pictures of the slimy monster were posted online by Reddit user 'xxviiparadiseto' to see if anyone could identify it.
"It weighed around seven pounds (3.2kgs) and if I had to guess about five inches (13cms) wide," xxviiparadiseto wrote.
One user speculated that it could be some kind of sea snail.
Another said, "Looks like whatever lives inside the seashell."
Reddit user PacificKestrel claimed to have solved the mystery. After asking if it was found in southern California, they said, "I'd say that, my friend, is a long-dead sea hare."
The California sea hare is a common species of sea slug found off the west coast of the US and northern Mexico.
They can grow up to 75cm long and can weigh as much as 7kg.
The slugs eat red algae from the sea floor, which turns them a reddish colour. It also grants them toxic properties meaning they have few natural predators in the ocean.
This is not the first bizarre sea creature to have sent the internet into meltdown this year.
In May, fisherman Asrul Tuanakota found a mysterious rotting carcass washed up on an Indonesian beach that left people baffled.
He discovered the 50ft (15m) creature on the northern shore of Seram Island. He guessed it was a giant squid because it appeared to be covered in tentacles.
Alexander Werth, a whale biologist at Hampden-Sydney College in Virginia, and George Leonard, chief scientist at the Ocean Conservancy, eventually solved the mystery.
The pair agreed the carcass was almost certainly a baleen whale. The bones protruding from the mass of rotting flesh appeared to be feeding plates from the whale's mouth used to filter food.