Son of Frankenstein (1939)

Wolfgang Frankenstein standing over his father’s sarcophagus.  He has just erased the word, “monsters” and replaced it with “men”.

Kit Maker: Unknown

From Wikipedia:

Son of Frankenstein is the third film in Universal Studios‘ Frankenstein series and the last to feature Boris Karloff as the Monster as well as the first to feature Bela Lugosi as Ygor.

The film was a reaction to the incredibly popular re-releases of Dracula and Frankenstein as a double-feature in 1938.^[1] Universal’s declining horror output was revitalized with the enormously successful Son, and the studio enjoyed two more decades of popular monster movies.