The film begins with footsteps leading to a pond. The camera continually moves upwards to show the flight of butterflies, birds, and a progression of historical aircraft ending with a rocket ship travelling through space and landing on the Moon. The astronaut/cosmonaut leaves his spacecraft and sights other footsteps on the Moon leading him to an old phonograph, then a crashed rocket with a plaque reading Jules Verne's From the Earth to the Moon. Taken to a dinner table, the surprised space traveller meets the characters from Verne's book and Baron Munchausen. Inviting him to their table, the characters believe that the cosmonaut is a man actually from the Moon, and kindly treat him as a small child. The Baron decides to take him to Earth in a fanciful airship held up by a herd of winged horses. The Baron dresses the spaceman, called "Tony" in the English dubbed version and "Tonik" in the original Czech, in 18th-century costume where they land in the 18th-century Ottoman Empire, in Constantinople. Speaking in an unintelligible voice that he calls the "language of diplomacy", the Baron presents Tonik to the Sultan. However, Tonik's lack of knowledge of diplomatic protocol and his falling in love with Princess Bianca, a damsel in distress held prisoner by the Sultan, leads to a series of romantic and fanciful adventures that transform the modern scientific space traveller into a hero rivalling the Baron. Among the exciting and satiric adventures are sword and sea battles with the Turks, being swallowed by a giant fish, and ending the conflict between two warring kingdoms.
The film was released internationally throughout the 1960s, including a 1964 American dub under The Fabulous Baron Munchausen. Howard Thompson of The New York Times described it as "a delectable oddity with a perky, intriguing music track," and writer Harlan Ellison termed it a "charming and sweethearted 1961 Czech fantasy filled with loopy special effects." César Santos Fontenla of :es:Triunfo |Triunfo called the film "a masterpiece" and added: "the film is undoubtedly the most exciting experiment so far in animation and in combining different techniques... The Méliès influence is present throughout the film, which reaches the same level of poetry as the works of that old master." Le Mondes film blog called Zeman's technique "perfectly fitted" to the Baron Munchausen stories, and described the result as "endowed with a splendid sense of humor and very inventive". The film historian Peter Hames described Baron Prášil as "perhaps finest film." When the film was screened at the British Film Institute in the 1980s, it served as an influence for Terry Gilliam, who was then making his own version of the Munchausen stories, The Adventures of Baron Munchausen. According to Gilliam: British magazine Home Cinema Choice voted The Fabulous Baron Munchausenthe best digitally restored film of 2017, defeating such films as The Thing, The Wages of Fear and Mulholland Drive.
