The entire dream sequence is an homage to the golden age of cinema musicals and includes references to Ziegfeld Follies (1945), Strangers in the Night (1966), Singin' in the Rain (1952) and Bathing Beauty (1944).
A picture on the wall has a caricature of Pierre Tchernia (co-script writer of the movie) as a prisoner being taken away by the guards. Pierre Tchernia made plenty of similar cameos in the Asterix series (also by René Goscinny).
Lucky Luke dose not sing his trademark "I'm a poor lonesome cowboy" song. However the tune of the song can be heard throughout the movie.
This is the first movie where Lucky Luke's horse Jolly Jumper is seen talking, much like in the original comic books and in fact is voiced by the co-creator René Goscinny in the French version.
The character of Dr. Aldous Smith is strongly based on W.C. Fields. The Lucky Luke comic book series already used a character based on W. C. Fields in the story "Western Circus".