The term lake monsters refers to mysterious beasts that are said to live in certain bodies of water. Among the best-known examples of such beasts are the Loch Ness monsters in Scotland, Ogopogo of Lake Okanagan in British Columbia, and Champ of Lake Champlain in the northeastern United States. There are, however, more than three hundred lakes believed to be inhabited by lake monsters; most are very deep and very cold, and the creatures themselves seem to have commonalities as well.

Typically, all are said to have elongated bodies, variously characterized as serpentlike, wormlike, or dragonlike. Usually they are said to move in an undulating fashion when on the surface of the water, which has led some cryptozoologists to speculate that lake monsters might actually be a zeuglodon, a snakelike primitive whale known to have existed but which most scientists say became extinct millions of years ago. There have been many reported sightings of lake monsters by credible witnesses, but none has ever been confirmed.

There have also been photographs taken of lake monsters, but skeptics dismiss all of them as fakes. Indeed, during the nineteenth century there were many confirmed hoaxes involving lake monsters. Moreover,throughout history there have been many sightings of lake monsters that later proved to be cases of mistaken identity.

The Greenhaven Encyclopedia of Paranormal Phemomena