By that time ‘Dracula’ was already plagiarized as ‘Nosferatu’ in 1922, since F.W. Murnau wasn't given the rights to adapt ‘Dracula’, so he shrugged his shoulders, changed a few things and made his own film. Inventing some stuff on the way like Nosferatu being affected by sunlight, about which Dracula and folklore vampires never gave a shit.

The 1931 ‘Dracula’ is notable partly due to its set having been used at nights to make a Spanish-language version in parallel. Which is considered better than the English-language one, because its crew had access to the English dailies and could check what worked and what didn't.