People have always been fascinated with the hidden, the mysterious, and the unexplained. Every society has its tall tales and ghost stories, its odd legends, and heroes. Also, every society has its stories of strange beasts, dangerous or benign, that live in the twilight world between the everyday and the legendary. Through most of history, people have been closely tied to nature, hunting in forests and having an intimate knowledge of the animals in their regions. So-called "primitive" peoples were walking encyclopedias of the natural world, and yet most believed there were more creatures lurking in those woods than the ones they usually encountered. Even as the world becomes more connected, the belief in strange creatures continues as strong as ever.

The willingness to believe in exotic animals has been so widespread that some have made careers out of displaying "oddities" to the public at circuses, fairs, and museums. Perhaps the most notorious individual to do this is P.T. Barnum, whose New York City museum was so popular in part because he was more than happy to invent items with which to fascinate the public, even if no such item actually existed. His first example of this was the now famous "Fiji mermaid." Barnum rented this oddity from a Boston rival, Moses Kimball, in 1842, but while the creature floating in the jar of formaldehyde was described as a mermaid, it was actually the body of a very young monkey with a fish tail sewn on over its legs. Barnum leased the item long term for $12.50 per week and then marketed it as having been caught by his friend Dr. J. Griffin, a pseudonym for Barnum's business associate Levi Lyman. For his part, Barnum saw nothing wrong with what he was doing, justifying the hoaxes by saying they were just "advertisements to draw attention...to the Museum...I don't believe in duping the public, but I believe in first attracting and then pleasing them."

Although cryptozoology is often scoffed at and widely considered a pseudoscience, one of the reasons it made men like P.T. Barnum rich and continues to fascinate people today is the fact that people realize they've only scratched the surface when it comes to identifying all the different forms of life on Earth. As Martin DelRio pointed out in The Loch Ness Monster, "Animals previously unknown to science have been found more than once in the past hundred years. For instance, there's the megamouth shark (megachasma pelagios), a fifteen-foot-long creature weighing nearly a ton. The first specimen was discovered on November 15, 1976, when it was found entangled in the drag anchor of a U.S. Navy ship. The new creature wasn't described scientifically until 1983...The megamouth remains the only species in its genus, and the only genus in its order."

While cryptids like Bigfoot and the Yeti have become popular in recent decades, none of them can touch the notoriety of the Loch Ness Monster, a large, unknown creature allegedly living in a loch in the Highlands of Scotland. Was it a relic dinosaur or perhaps an entirely new species? New photographs and new eyewitness sightings fueled a growing debate and transformed the Loch Ness Monster, also known as Nessie, into an instantly recognizable staple of pop culture, to the extent that hundreds of thousands of visitors came to Loch Ness every year in hopes of catching a glimpse of the loch's famous inhabitant.

The Loch Ness Monster remains an international brand and the best-known cryptid in the world, but after almost 100 years of fame and media attention, what do people really know about this cryptid, and is there any proof that there really is something large and unknown living in a remote Scottish loch?