Mad scientist Mickey has just brewed up a potion; to test it out, he squirts it on a fly that's been trapped by a spider, a (regular) mouse being harassed by a cat, then the cat when Pluto goes after it, and Pluto when dogcatcher Pegleg Pete goes after him. Each of the underdogs turns against his tormentor.
Walt Disney
as Mickey Mouse (voice) (uncredited)
Pinto Colvig
as Pluto (voice) (uncredited)
Billy Bletcher
as Pete - Dog Catcher (voice) (uncredited)
Clarence Nash
as Spider / Cat (voice) (uncredited)
