I must say, I am a big fan of monster movies. But this Mash-Up really is too much salt in the soup.
The problem that a movie faces, containing a few of the most profilic monsters in literature and cinema history, is obvious. You cannot possibly cast well-known or good actors for all of the creatures. Only Lon Chaney Jr. reprises his role of the Wolfman, while the Frankenstein monster and Dracula are portrayed by other, stinking actors. A fact that clearly sucks down the quality of this flick.
The strongest part of the movie is of course Boris Karloff, who oddly enough does not play the monster itself, but Dr. Gustav Nieman, a mad scientiest who, after having escaped from prison, treks through the country to A) Find Victor Frankenstein's records and B) Return to his lab and continue his experiments.
On his way he and his hunchback (besides kidnapping a gypsy woman) revive none other than Dracula, the Wolfman and the Frankenstein monster.
Of course, these abnormal beings cannot possibly get along and despise each other, partly over a colliding love interest with the gypsy woman.
It is a pity that not in ONE scene the three classic monsters fight against each other, which is a really a major stupid decision if you've already decided to throw them all into the same bowl alright.
How could a final fight between Dracula, Wolfman and The Monster had been a highlight in creature cinema.
Another basic rule of classic horror was not applied. You cannot have a strong antagonist without an equal protagonist and vice versa. I missed Van Helsing or a hard-boiled police constable.
All in all, compared to classic movies of the early Universal or later Hammer era, this nugget really does not shine. It is a chuckling laugh at most.
"I'm going to give that brain of yours a new home in the skull of the Frankenstein monster. As for you, I'm going to give you the brain of the wolfman so that all your waking hours will be spent in untold agony awaiting the full of the moon... which will change you into a werewolf."