4. The Great Sea Serpent
According to eyewitnesses, this behemoth of the deep was spotted off the coast of Maine in 1974. Measuring over 1,000 feet in length, the creature reportedly left a trail of bubbles and destroyed three fishing boats.
Witnesses described it as having "a head like a giant turtle, a body like a snake, and a tail like a... well, a tail."
Some speculate that this may have been an escaped creature from the depths of the Mariana Trench, while others claim it was actually a prank by the Sea Monster Appreciation Society.