Trivia: During the scene where a drunken Uncle Billy walks home, a loud crashing sound is heard. The crashing sound was due to a crew member dropping a large tray of props. Thomas Mitchell quickly ad-libbed the line that he was all right. The crew member who dropped the tray was afraid he would be fired but instead director Frank Capra gave the crewman a ten dollar bonus for "improving the sound."
Trivia: At the end of the movie Lauren Bacall says to Marlowe "Phil, there's two men out back behind some trees". This is the only time in the movie that she refers to him by his first name. (01:49:45)
Trivia: When Porky is walking past the movie theatre, all of the film posters have moustaches drawn on them. You can see a poster of Warner Brothers star Bugs Bunny with a moustache at the ticket office.
Trivia: Leopoldine Konstantin plays Claude Rains' mother in the movie, even though in real life she was only three years older than him.
Trivia: At the start of the cartoon, we see animals changing seats in the theatre. This is re-used footage from a 1937 Warner Brothers cartoon, "She Was An Acrobat's Daughter."
Trivia: The "Evil Scientist" in this cartoon is a caricature of the actor Peter Lorre.
Trivia: When we see Bugs Bunny for the first time, behind him on the ballpark fence there is a picture of a man with a gun and a detective hat with the words "Mike Maltese, Ace Dick" written nearby. Michael Maltese was the writer for this cartoon.
Trivia: As the gangsters speed by in their red car, you can see a billboard along the road advertising "Hotel Friz" - a reference to the director Friz Freleng.
Trivia: At the beginning of the cartoon, we see a long line of books at the book shop. The last book we see is entitled "Life and Times" by Bugs Bunny.
Trivia: When we see Daffy's silhouette in the door of Duck Twacy's office at the start of the dream sequence, the silhouette of Daffy briefly changes twice into Dick Tracy's silhouette.
Trivia: When Tom woos the dog instead of the cat, he says the exact same dialogue he used in a previous Tom and Jerry cartoon, "Zoot Cat" (1944).
Trivia: "Lonesome Lenny" was the final Screwy Squirrel cartoon made by MGM.
Trivia: When Jerry finds Butch in the alley, we hear Butch humming a song. The song he is humming is "Over the Rainbow" from the film "The Wizard of Oz."