The world's largest stuffed horse is reputably "General," on display at the Virginia State Farm Museum in Point Pleasant, West Virginia.  According to Roadside America:

"General," who looks like Mr. Ed, was the third heaviest (2850 pounds) and third tallest (six feet, six inches) horse ever recorded. And he is still the world's largest stuffed horse, at a cost of $10,000, according to one of the many helpful signs around the stable. Despite his size, another sign insists that General was "gentle as a puppy." Yet another sign claims that his stuffed hide is valued at $25,000, a low estimate in our eyes. A newspaper clipping from 1982 quotes a local bigwig as saying that General, once stuffed, would make a sure-fire tourist attraction.

Check out all the delights of the museum including a two-headed calf that froze to death in the winter of 1926.  [Go +]