Here are two more curiosities in which fictional characters are described as having had real lives, though both are only seen as ghosts.

 In the Filmation GHOSTBUSTERS episode "The Headless Horseman Caper," the heroes encounter a ghost who appears based on the legend of the Hessian soldier recounted in "The Legend of Sleepy Hollow," but without the disturbing detail of getting his head blown off in battle. The cartoon just says he's some ghost-- not even given any specific military designation--...