The shelved Donald-Scrooge Opus is an unproduced animated Donald Duck short that was to have been Scrooge McDuck's animated debut. Disney Legend Carl Barks, who had created Scrooge in 1947, was apporached to contribute to his character's introduction to animation by the Disney Studios, and worked on a detailed script and storyboard sketches.
Late in 1954, Carl Barks was asked by the Disney Studios if he would be free to write a script for a Scrooge McDuck 7-minute animated cartoon. Scrooge was a huge success in the comic books at the time, and Disney now wanted to introduce the miserly duck to theater audiences as well. Barks supplied the studios with a detailed 9-page script, which was accompanied by a synopsis telling the story of the happy-go-lucky Donald Duck working for the troubled Scrooge who tries to save his money from a hungry rat. Barks also sent some sketches of his ideas for the short, including a money-sorting machine, a concept which Barks had already incorporated in the cover of one of the Uncle Scrooge issues.
The script was never used, as Disney soon after decided to concentrate on TV shows instead.
Donald works at Scrooge's Money Bin, operating a money-sorting machine that runs by power. When Donald is away at lunch, the radio announces a plague of rats is loose in the city. Scrooge closes and shutters all of his windows and bolts the door. He sits down terrified to eat his cheese sandwich but, before he can begin, he is besieged by a determined rat who has smelled the cheese from afar. The rat threatens to destroy a $10,000-dollar bill, if Scrooge doesn't order the most expensive cheese in the world.