Found a clip of this cartoon on Tumblr today. When I clicked on the image I was bumped to youtube where I watched the whole thing. It involves Micky trying to rescue Pluto from the lair of a mad doctor. According to Wikipedia: "The short's horror overtones made it unusual for a Micky Mouse cartoon. Some theaters refused to show it, believing it to be too scary for kids. At one time, for this reason, it was banned entirely in the United Kingdom."
