Liam Dunn died during the filming of the roller rink sequence. John Fiedler was brought in to complete the role as dog catcher.
In addition to a basset hound which sounds like Humphrey Bogart, the other animal shelter scene features dogs whose "additional voice characterizations" were impressions of James Cagney, Edward G. Robinson, Peter Lorre and Mae West. The voices were provided by impressionist George Kirby.
Dean Jones practiced the faces he pulled in the transformation scenes during the time his make-up was being applied.
The $2000 Wilby offers as a reward for the ring adjusted for inflation is $10,410 in 2022.