The Great White Shark
If there's an Elvis of the shark world, the Great White is it, hands down. It starred in the movie "Jaws," is the embodiment of predation, and its very existence makes ocean swimmers nervous.
Great whites live in coastal waters and offshore in many locations worldwide -- wherever the water's sufficiently warm. In the United States, they can range from Alaska to California on the west coast and all along the east coast, Gulf coast, and Hawaii.
In unusual cases, great whites can be around 20 feet long and weigh more than 7,000 pounds. More typically, though, males will be around 13 feet long and the females just over 16 feet long. Not that that's tiny: Great white pups, even right at birth, can be 5 feet long! And, while it is indeed great, it's only white on its belly, with the topside usually gray to bluish-gray.
What do great whites eat? How about anything they can? Other sharks, sea turtles, birds, porpoises, seals, and tuna are just a few members of the undersea community that could end up a great white's next meal. The enormous sharks dive past 4,000 feet, so there are few places for marine life to hide from this voracious predator. And, helping its cause, the great white has no natural predators apart from Orcas.
Notwithstanding their dominance, great white still know a thing or two about the need for caution. Its eyeballs will move to the back of its head when it is in attack mode, to help protect its eyesight.