Some cryptids attract hoaxes much more than others, the two greatest examples of these being Bigfoot in America and the Loch Ness Monster in Scotland. These hoaxes are not, in my opinion, humbug and jolity like the hoaxes of Barnum and his peers, for they serve to constantly chip away at any credibility these cryptids may have. The crypids are contently targeted purely by the virtue that they are well known and the huge amount of hoaxes leads people to believe that because there are so many hoaxes then there is probably no truth behind any of the reports. When a person does see something that they think may be Nessie they now will automatically assume that it was a floating log or a wave and not report it. It may well have been a floating log, but what if it really was a sighting of an unknown animal? The evidence would be lost forever.
Particularly irksome is when hoaxes like this are preformed as publicity stunts to market some tawdrey wares. Sometimes they even try to use hoaxes like this to attempt to promote something that may have been of interest to real cryptozoologists, scoring a spectacular own goal in the process. One such incident occurred during the publicity campaign for Steve Alten's book The Loch.
In March 2005 the story broke that 2 American tourists had found a strange and quite large tooth on the banks of Loch Ness. They took photographs of the tooth but as they were doing so a shady water bailiff came up to them and confiscated the tooth, which was never seen again!
This might perhaps sound just within the realms of possibility to some but the story lost any credibility it may have had when you saw the photos of this alleged tooth. It was not even a tooth, rather the tip of a stag's antler. Pretty soon the hoax was admitted to as part of the book's publicity campaign. Perhaps the people responsible were expecting this to get people talking about Loch Ness and the book and for sales to go through the roof.
Well, they were part right: people did talk but mostly about what an idiotic thing to do this was and vowing never to buy the book. Obviously with the publicity generated the book's sales would have improved over what the sales would have been but had they not annoyed a large part of their target audience and thought of a better way of getting publicity the sales could have been higher.