Those walking along Crystal Cove in California might have encountered a scene straight out of the movie "Alien" when they found this fish washed up on the shore.

Nightmare fish

The large obsidian creature had its mouth agape, displaying a set of sharp teeth, and a long appendage covered in tentacles protruding from its head.

Here's a look at its full body, which is covered in short spines.

Tim Burton will approve.

A tweet by Davey's Locker, a U.S. company that offers whale-watching and fishing excursions, revealed that the monstrous-looking fish is actually a type of deep sea anglerfish, known as a Pacific footballfish.

Crystal Cove State Park staff were alerted to the rare discovery by beach visitor Ben Estes, and subsequently retrieved the specimen intact.

Since the tweet was posted on May 9, it has amassed 959 retweets, with many users marvelling at the fish's appearance.

RARE FIND! Deep sea anglerfish washed up in Newport Beach on Friday morning! On Crystal Cove beach @CrystalCoveSP staff were alerted by beach visitor Ben Eslef and were able to retrieve this intact specimen.. pic.twitter.com/vERGy5Zujt

— Davey's Locker (@DaveysLocker400) May 9, 2021

Lives at depths between 600m to 900m

Estes told The Guardian that although he was a regular beachgoer and fisherman, this was the first time he had seen such a fish.

Davey's Locker explained in a Facebook post that although footballfish are not exactly rare, it was rare to find a specimen preserved so perfectly on the beach.

The footballfish is a species that lives roughly 600m to 900m deep in the Pacific Ocean, where light is non-existent.

At such depths, food is scarce, and footballfish use the lure dangling on its head to get prey.

The tips of the lure are bioluminescent, and this tiny light source attracts food in the form of other fish, squid and crustaceans.

The individual found on the beach is around 18 inches, or 45cm, wide.

Footballfish display extreme sexual dimorphism, meaning that males and females have drastically differing appearances.

Females are much larger than males — in this case, the individual found is a female — with the latter only growing to a size of around 4cm.

The males are also known as "sexual parasites" — when they find a female, they will fuse to the side of the female's body and its eyes and other organs will degenerate, leaving behind only its testes.

Davey's Locker added that it is unclear where this rare find will end up — either with museums or educational institutions. It is currently housed with the California Department of Fish & Wildlife.

"Finding Nemo" antagonist

The footballfish has made several pop culture appearances.

It featured in Pixar's "Finding Nemo".

It is also possible to catch a footballfish in the popular Nintendo Switch game "Animal Crossings: New Horizon".

Top photo from Davey's Locker