The creature resembles that of what are known as plesiosaurs. Mainstream science agrees that plesiosaurs became extinct millions of years ago, however believers point to photographic and video evidence of the alleged being as being proof.
It must be said that people are intrinsically fascinated by the unknown and the possibility that creatures such as the loch ness monster actually exist. The want to believe, however, does not make something true. Scientists will be quick to point out that a large aquatic reptile such as a plesiosaur would have a difficult time attempting to survive the freezing cold waters of the Scottish lake. Also, unless the Loch Ness monster is a fish, it would need to surface regularly to breath, just as alligartors do.
Not only would a single giant reptile be easy to spot eventually, but more than one Nessie is needed to have survived all this time. The Loch Ness monster could not have been just a single creature that survived for thousands of years. And if there are several Nessies swimming around in the Loch Ness, why is it so hard to spot just a single one of these creatures?
Animals also die, so the question as to why not a single carcass of such an animal hasn't yet been found needs to be asked.
Admittingly, every now and then new species of large aquatic creatures are found. The megamouth shark was thought to have been extinct for millions of years and was found to still be living just 40 years ago. The problem is, however, that these animals lived in the ocean which is a very unexplored part of our planet.
So does the Loch Ness Monster exist? The odds are against the existence of a plesiosaur existing in the Loch Ness, but anything's possible!