10. Glenn Strange was playing the Frankenstein monster, but during shooting one day he tripped over a camera cable and broke his ankle. Lon Chaney Jr. (playing the Wolf Man) wasn’t working that day, so he put on the Frankenstein makeup/outfit and filled in for Strange in one scene.
9. Even though actors Bela Lugosi, Lon Chaney Jr. and Glenn Strange all reprise their roles from earlier films this particular film is not considered to be part of the continued Universal Monsters storyline
8. Glenn Strange speaks for the first time as The Monster.
7. For the first time, Universal-International stopped using the effective but lengthy application time of make-up artist Jack P. Pierce for the monster make-up, using Bud Westmore and Jack Kevan’s more cost-effective rubber appliances
6. The animation sequences of Dracula-as-a-bat and Dracula-changing-from-bat-to-Dracula were done by Universal-International’s animator, Walter Lantz (of Woody Woodpecker fame)
5. Boris Karloff was never approached to play the monster, but as a favor to Universal, he agreed to do publicity work for this film as long as he didn’t have to see the film
4. Three actors in this film had previously played the Frankenstein Monster. Aside from Glenn Strange who actually plays the role again, both Bela Lugosi and Lon Chaney Jr. had experience under the flat top as well.
3. Lou Costello did not want to film the movie, declaring, “No way I’ll do that crap. My little girl could write something better than this.” A $50,000 advance in salary and the signing of director Charles Barton, the team’s good friend and the man whom some call their best director, convinced him otherwise
2. Originally the Mummy was to be included in the cast of monsters, but that idea was eventually dropped.
1. The scene in which Wilbur is unknowingly sitting on the Frankenstein Monster’s lap required multiple takes. The scene allowed Costello to improvise wildly, which caused Strange to constantly break up laughing during the takes.