Abbott and Costello play two freight handlers who are being chased by the Frankenstein Monster, Dracula and The Wolfman. Dracula plans to take Costello's brain and put in the monsters head. It's a silly plot but this whole movie really makes you buy into the silliness. By the way, why is this called "Abbott And Costello Meet Frankenstein", why couldn't they call it "Abbott And Costello Meet The Monsters"? Alright it's a nitpick but still it would've been a better title.
Lets start with the Monsters. Well instead of being goofy and over the top, they're actually played just as serious and scary as they were in the original classics. Bela Lugosi reprises his role as Dracula for the second and final time in his film career. Just like in the film, he's classy, scary and his eyes are still frightening. We also get to see him change into a Bat right in front of our eyes. Lon Chaney Jr. plays The Wolfman just as seriously and scary as he did in the films. The Monster is sadly not played by Boris Karloff, however, the actor playing him is still good at being scary, the make up on him is just as great as the original classics and Lon Chaney Jr. plays him in one scene when the monster attacks Dracula's slave. The film is not really a follow up to the films or stories where the Monsters die at the end, so there's really no continuity even when Dracula casts a reflection on the mirror. I will say this however, the Monsters fate was very anti climatic. There's another monster that appears in the end but I don't think you'll see him.
Now for the Duo, are they funny in this film? I actually think this one of their best films of all time. They share great chemistry together as usual, they have funny dialogue, a little slapstick, a few chases and some improv as well. Their best bits is when Costello sees the Monsters while Abbott thinks he's being crazy. The comedy with them in this film doesn't get old and only gets better. As for the film itself, it has great horror looking sets, creepy music, fun and scary cinematography, animation from Walter Lantz who did Woody Woodpecker and the supporting characters while not being to memorable they're still fun and likable.
The film has a great mix between horror and comedy and all it takes is a famous duo and classic monsters. One of Abbott and Costello's funniest films.