Sydney Carton, the man with the different-sized feet whom Foots Pulardos (Telly Savalas) planned to kill and pass off as his own corpse, is a reference to the character Sydney Carton in Charles Dickens' "A Tale of Two Cities", who meets his fate under identity swapping circumstances.
The name of the German Shepherd, for whom Ernest Klenk (Danny Kaye) approved a Diners' Club card, is Maurice Baskerville, a reference to the famous Sherlock Holmes novel "The Hound of the Baskervilles", written by Sir Arthur Conan Doyle.
Persistent rumors (never confirmed) about this film suggest that it was originally intended as a vehicle for Jerry Lewis, and ended up starring Danny Kaye instead. Lewis made many films with Director Frank Tashlin, and they had a success (written by John Fenton Murray, who also worked on this film) with It's Only Money (1962). Many critics noted that the physical comedy involved in this film would have seemed more suited to a younger man than the fifty-year-old Kaye, Lewis was fifteen years younger than him.