Sea serpent is said to be a large ocean creature that looks like a huge snake. Since ancient times, people have told tales of such creatures. For example, many Asian myths tell of serpentlike dragons that live beneath the sea. These dragons cause storms. The Bible describes Leviathan, a giant sea serpent.
In modern times, witnesses have reported seeing sea serpents. These are often described as a series of dark humps appearing among the waves. However, no snakelike monster has ever been caught or washed ashore. Scientists think most people are actually seeing an optical illusion caused by waves. Or possibly people may have seen a school of porpoises. Other sea animals, including eels, sharks, and giant squids, have also been mistaken for sea serpents.