The 18-inch sea creature has been identified as a Pacific footballfish, which normally lives in darkness 2,000 to 3,000 feet under the Pacific Ocean.
The fish itself is not rare, but it is unusual to find a fully intact specimen washed up on a California beach.
It was found Friday by a visitor to Crystal Cove State Park in Newport Beach.
The Pacific footballfish is one of some 300 species of anglerfish found around the world.
Officials with the state park described some of the fish's attributes in a Facebook post:
"Only females possess a long stalk on the head with bioluminescent tips used as a lure to entice prey in the darkness of waters as deep as 3,000 feet! Their teeth, like pointed shards of glass, are transparent and their large mouth is capable of sucking up and swallowing prey the size of their own body."
"While females can reach lengths of 24 inches males only grow to be about an inch long and their sole purpose is to find a female and help her reproduce. Males latch onto the female with their teeth and become 'sexual parasites,' eventually coalescing with the female until nothing is left of their form but their testes for reproduction. Wild!"
"To see an actual angler fish intact is very rare and it is unknown how or why the fish ended up on the shore. Seeing this strange and fascinating fish is a testament to the diversity of marine life lurking below the water's surface in California's MPAs and as scientists continue to learn more about these deep sea creatures it's important to reflect on how much is still to be learned from our wonderful ocean."
The body of the fish is expected to end up with a research or educational organization. It is currently being held by the California Department of Fish & Wildlife.