What are “long-tailed heroes”?

In the book Roughing It, Mark Twain refers to gunfighters as “long-tailed heroes.” What does that mean? Paul Gortarez Phoenix, Arizona Twain was referring to the frock-coat-wearing gunfighters who prowled the streets of Virginia City. Let’s let Mr. Twain tell the story: “The deference that was paid to a desperado of wide reputation, and who ‘kept his favorite graveyard,’ as the phrase went, was marked, and cheerfully accorded. When he moved along the sidewalks in his excessively l