Trivia

In the documentary, Listen to Me Marlon (2015), Marlon Brando called this movie "the worst movie I ever made in my life."

James Coburn's character is called "Dr. Krankeit": "Krankheit" means "illness" in German. "Dr. Kronkheit" is also the name of a celebrated vaudeville routine, in which a patient visits an inept doctor ("Kronkheit" is the Yiddish equivalent). This sketch was made famous by Joe Smith and Charles Dale, who can be seen performing it in Two Tickets to Broadway (1951); it was reprised in The Sunshine Boys (1975) by Walter Matthau and George Burns.

Buck Henry wrote MacPhisto's (Richard Burton) poem as a parody of Dylan Thomas.

In one sequence, the Hunchback Juggler (Charles Aznavour) escapes the police by crawling on the mansion ceiling and jumping down through a window made of water. This is a visual reference to surrealist Jean Cocteau's The Blood of a Poet (1932) where the character jumps into a mirror made of water after crawling over a hallway of doors (the effect was achieved by constructing the "wall" and "ceiling" on the studio floor and shooting the scene from above). Even the sound effect at that moment, a shouted "No!", is in both movies.

This movie was entirely financed thanks to Marlon Brando's participation and his presence brought the other actors in.Director Christian Marquand and Brando had known each other for a long time and were good friends. Brando agreed to do this movie as a favor to his friend. Marquand had used his connections and helped with negotiations with the French Premier Georges Pompidou in Brando's purchase of the Tahitian island of Tetiaroa. He didn't particularly like the script but he had fun shooting his sequence. Then other stars agreed to play a part in the movie and it was even easier to convince the producers. One of the people who opposed Brando's purchase of Tetiaroa was the head of the Tahitian Territorial Assembly, Jacques Denis Drollet, whose son Dag later had a baby boy with Marlon's daughter Cheyenne,and was subsequently shot to death in a struggle with Marlon's son Christian after Cheyenne allegedly accused Dag of abuse. (Brando The Biography by Peter Manso pg.634-635)

Buck Henry: The screenwriter is the strait-jacketed man in the elevator who becomes agitated at the mention of Dr. A.B. Krankeit (James Coburn).