The Fifth Column Mouse (1943)

The Fifth-Column Mouse[a] is a 1943 Warner Bros. Merrie Melodies animated cartoon directed by Friz Freleng. The short was released on March 6, 1943.
The cartoon features a band of mice who engage in war against a cat. This is a wartime propaganda film, with the cat symbolizing the Axis powers. A single mouse represents the fifth column, working for the cat and suggesting an appeasement policy.