Imagine a shark that grows as large as a great white, has toxic, urea-soaked flesh, and dines on an assortment of marine mammals.

No, this isn't the latest Hollywood attempt to ramp up the "Jaws" franchise. Meet the Greenland shark — perhaps one of the world's least known apex marine predators.

Daredevil diver Doug Perrine recently had the audacity to get up close and personal with one of these elusive creatures, according to the Daily Mail. Though the water was murky and cold, Perrine took solace in the fact that these sharks are not known to attack humans — but they aren't known for good eyesight, either.

"The sharks were able to satisfy their curiosity about me by approaching to the limit of visibility at about six meters distance," Perrine told the Daily Mail. "The sharks are known to prey on large seals, but I never felt threatened."

"They have an almost goofy, comical appearance," he added, referring to the animal's toothy grin — an expression that seems etched in stone upon their faces.

The Greenland shark is native to the waters of the north Atlantic Ocean, living farther north than any other shark species. Perhaps the lack of competition is what drives them to feast on such a vast array of Arctic prey, a menu which typically includes fish and marine mammals, but because this creature is primarily a scavenger, some specimens have been found with horse and reindeer in their stomachs.

One of the shark's other unusual attributes includes its poisonous, urea-laced flesh, which makes the animal hazardous to eat. Interestingly, the toxic content of its flesh comes not from the urea, but rather from the presence of trimethylamine oxide, a toxin that can produce symptoms similar to drunkenness when consumed. Even so, local Inuits have learned to make the flesh palatable by boiling it or fermenting it for several months.

The shark is also known to live for as long as 200 years. The oldest individuals are the ones known to reach massive sizes (possibly as long as 24 feet), rivaling the great white shark.

Check out a video below for a (safe) glimpse of what it's like to swim with one of these eerie Arctic predators: