Divers Catch Rare Close-Up Glimpse of Giant Sunfish

Divers have come face-to-face with a monster from the deep - a sunfish.

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The fish measures 15-by-12 feet and is believed to weigh as much as 5,000 pounds.

It almost looks like a creature from another planet and its mouth never closes. The fish is considered a delicacy in Japan.

The extraordinary video was made off the coast of Portugal.

Read: 9-Year-Old Catches 600-Pound Fish

Corbin Maxi, a marine biologist, told INSIDE EDITION: "Seeing this was a great rare experience and the footage is absolutely incredible. They can get literally the size of a truck. They look intimidating but they are completely harmless to humans and are actually curious with divers." 

Sunfish are the heaviest fish in the ocean, by weight.

The real king of the sea is the whale shark. The gentle giants can measure 40 feet and weigh 45,000 pounds making the sunfish smallfry by comparison.

Watch Below: Fearless Fisherwoman Swims at Sharks While Hunting Her Prey Underwater

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