In the film, Rufus T. Firefly, portrayed by Groucho Marx, is a wise-cracking and irreverent political outsider who is unexpectedly appointed as the leader of the small, fictional country of Freedonia. Despite his lack of political experience and decorum, Firefly quickly sets about enacting sweeping changes that endear him to the Freedonian people, including renaming their currency to the "banana" and appointing his incompetent friends as key members of his administration.
Meanwhile, wealthy widow Mrs. Teasdale, played by Margaret Dumont, pledges to donate a large sum of money to help bail out Freedonia's bankrupt government, provided that Firefly is named the country's leader. However, Firefly's antics soon land him in hot water with neighboring country Sylvania, whose leader, Ambassador Trentino (Louis Calhern), is intent on taking advantage of Freedonia's political turmoil to annex the small country.
As tensions between the two countries escalate, Firefly and his madcap cohorts engage in a series of absurd and hilarious antics, including a chaotic courtroom scene, a dance number featuring a chorus line of soldiers, and a climactic battle scene that includes everything from banana peels to a giant accordion.
Despite their initial difficulties, Firefly eventually manages to broker a peace treaty with Sylvania, thanks in part to the help of Mrs. Teasdale, who he has fallen in love with. However, in a classic Marx Brothers twist, Firefly then promptly proceeds to declare war on another neighboring country, suggesting that Freedonia's political situation may be just as unpredictable and ludicrous as its new leader.
