Myth. I don't believe in the Loch Ness Monster, the Abominable Snowman, ghosts, or any other creatures that allegedly exist. Until there's hard evidence proven by so and so scientific research laboratory to back up the existence of these alleged creatures, I'd like to pin them as pure mythology.
I don't believe there was any evidence to prove the existence of the Loch Ness Monster nor the Abominable Snowman. I know there are photographs, but most, if not all, turned out to be hoaxes anyways, so I don't deem photographs as hard evidence. The reason why none of these creatures were caught? Simple - they don't exist. Besides, if people really did believe the Loch Ness Monster existed, I'm pretty sure the science-crazed activists would have sucked out all the water in the Loch Ness by now.