A man on a California beach thought he saw a jellyfish. It was a rare deep sea monster.

A man saw something out of a nightmare when a deep sea monster washed up on a San Diego beach.

According to KGTV, Jay Beiler was walking on Black's Beach on Nov. 13 when he spotted a scary-looking fish he thought was a jellyfish.

A closer look revealed it was a Pacific footballfish – a fish that lives in the Pacific Ocean at depths of 2,000 to 3,300 feet where sunlight doesn't penetrate, according to the California Academy of Sciences.

They have needle-sharp teeth that point inward, and some male footballfish attach themselves to females as "sexual parasites," losing all their eyes and internal organs except for testes, the site said.

“I have never seen anything quite like this before,” Beiler told NBC San Diego. “You know, I go to the beach fairly often, so I’m familiar with the territory, but I’ve never seen an organism that looked quite as fearsome as this.”

Pacific footballfish are a part of the anglerfish species that can grow over 3 feet long and weigh up to 110 pounds, according to National Geographic.

Ben Frable, collection manager at the Scripps Institution of Oceanography, told NBC San Diego that the last time a member of its species was found on a San Diego beach was in 2001.

He told the outlet he planned to find the footballfish seen by Beiler, but crabs and seagulls most likely got to the deep sea creature first.

"We don’t know much about the biology of these fishes, and that's one of the reasons we would like people to let us know when they find one on the beach so we can potentially learn a little bit more,” Frable told NBC San Diego.

Follow reporter Asha Gilbert @Coastalasha. Email: agilbert@usatoday.com.

This article originally appeared on USA TODAY: Rare deep sea monster fish washes up on San Diego beach