Not really, but almost. The evil doctor Niemann (Boris Karloff) and his faithful assistant Igor ... I mean Daniel (J. Carrol Naish) escape from prison, commandeer a travelling circus, and head for Visaria in order to take up the good doctor Frankenstein's work. Said circus also happens to feature the bones of Dracula (John Carradine), which if you take the stake out, his evil body reappears.
While searching for Frankenstein's notes in his demolished mansion, they stumble across the body of the Monster (Glenn Strange) and the Wolf Man (Lon Chaney Jr). Stop me if you heard this one before. Anyhow, Niemann promises Daniel a proper body so that he can woo this hot gypsy chick, promises to keep Dracula's coffin safe during the day, and promises Wolfie that he will kill him. Instead, the douche, he totally uses his new circle of friends to work on his real project: getting the monster back to full strength and killing the people who sent him to prison. And what would a Frankenstein flick be without Lionel Atwill in there someplace. Once again, he plays an inspector.
So, Karloff took a break from Broadway to appear in the movie, but apparently Lugosi wasn't free. Seems he took up Boris' role. Therefore, Carradine becomes a lackluster Dracula. And speaking of which, what, was he in the movie a whole four minutes? The only reason I can imagine for his appearance is to make the movie poster more crowded with monsters and to introduce him for the next movie. I understand there was a thought to include The Mummy as well, but that would have been ridiculous.
A few interesting points: As this movie mostly takes place in "Visaria", which sounds like "Vasaria" where Ghost Of was set, the evil doctor house is that of the other brother's, and he was the least evil of all the Frankenstein's. Nobody from the actual family appears, unless you count the Monster. George Zucco had a small part as the circus owner. I had to go online to find out what role he played. It was all too brief. And, Chaney, Strange, and Naish all died in 1973. Chaney and Naish's collective last movie was the schlocky Dracula vs. Frankenstein, which I totally have to watch.
Thirteen years after the advent of Universal's reign as the king of horror, we are seeing their demise. The appearance of a large, slow moving creature isn't enough to scare audiences anymore and compensating with a monster mash has limited appeal. There is one more, however, but I will explore that with the Dracula line. Eventually.