A few years back, this guy showed up in a few headlines, mostly in England:
Supposedly, it was found in someone's garage, and they asked their friend, Allistair Mitchell to investigate it, and he speculated that German scientists could have attempted to hoax the English near the end of the 19th century, and that it was offerred to the Natural History Museum, but they dismissed it, and ordered it to be destroyed, and if it weren't for a museum porter (a distant relative of the guy who discovered it in his garage, of course), the entire thing would have been lost forever.
This article, published in January 2004, gives more information....while this article, published in March of the same year, reveals the entire thing to be a publicity stunt created by Mitchell to generate excitement for an upcoming novel of his.
I can't really say whether or not it worked for him, but it's pretty interesting that this approach was taken to sell some books. What is more interesting is all the forums and websites the dragon in a jar showed up on (just do a search for it), and all the people who were hoping it was real.
The dragon, by the way, was created by Crawley Creatures, a cinematic creature, robotics, and prosthetics company.