The largest shark that ever lived, the Megalodon terrorized the oceans for 20 million years with jaws wide enough to swallow a great white whole. At 60 feet long and 50 tons, its bite force exceeded 40,000 pounds—the strongest of any creature to ever exist on this planet. It went extinct three million years ago, and every ocean swimmer silently thanks evolution for that every single day.

Known as the killer whale despite technically being the world's largest dolphin, the orca is the ocean's most intelligent and ruthless predator. Hunting in pods with coordinated strategies that include creating waves to wash seals off ice floes, they've been observed killing great white sharks purely for their livers. The apex predator of apex predators—nothing in the sea hunts an orca.