a.k.a. Bud Abbott and Lou Costello Meet Frankenstein
Postal workers Wilbur (Lou Costello) and Chick (Bud Abbott) make a delivery to McDougal's House of Horrors, a wax museum, not knowing the crates they're carrying contain the bodies of Dracula (Bela Lugosi) and Frankenstein's monster (Glenn Strange). After Dracula rises from the dead (or the crate), Wilbur looks inside the other crate; Dracula hypnotizes Wilbur, then takes off with the monster to Dracula's remote island castle. Museum owner McDougal (Frank Ferguson) arrives and, seeing the empty crates, thinks Wilbur and Chick have stolen their contents.
Meanwhile, back at the castle, Dracula and the monster are making plans with a woman named Sandra Mornay (Lenore Aubert) to transplant Wilbur's brain into the monster's skull. Meanwhile, Larry Talbot, better known as the Wolf Man (Lon Chaney, Jr.), tells Wilbur and Chick about the plan, then has the boys lock him inside his room for the night so he can't hurt anybody when the full moon rises.
The next day, Joan Raymond (Jane Randolph), an investigator working for McDougal, flirts with Wilbur in an effort to learn where he's hidden the supposed wax figures belonging to McDougal. Wilbur ends up taking her to a fancy-dress party, even though he already has a date with Sandra (who he believes in his girlfriend, when Sandra is really just cozying up to him to get his brain). While waiting for Sandra to dress for their date, Wilbur gets a call from Talbot telling him that Dracula and the monster are somewhere in the castle. Wilbur searches for them, finds them, gets chased around by them...
Meanwhile, Sandra finds out what Joan is really up to, so Dracula hypnotizes Joan — but ends up biting Sandra, turning her into a vampire. Meanwhile, Talbot turns into the Wolf Man and attacks McDougal, who thinks Talbot is Chick (who dressed as a wolf for the costume party).
There's a big chase through the woods; Dracula captures Wilbur and Joan and takes them back to the castle. Just as Sandra is about to transplant Wilbur's brain into the monster, Chick and Talbot arrive to save him — but not before Talbot turns into a werewolf again. The monster breaks loose and throws Sandra out the window while Wilbur and Chick make a run for it, and while Wolf Man Talbot chases Dracula outside and into the ocean, where they both drown, breaking every silver-bullet and wooden-stake rule of every werewolf and vampire movie in history.
Joan comes out of her trance, and she and the castle's resident Igor, Dr. Stevens (Charles Bradstreet), burn the monster to death. Wilbur and Chick escape on a boat, only to realize that they have a passenger: the Invisible Man (voice of Vincent Price).
Bride of Frankenstein (1935)
Dracula's Daughter (1936) We need a spoiler!
Son of Frankenstein (1939) We need a spoiler!
The Wolf Man (1941)
The Ghost of Frankenstein (1942) We need a spoiler!
Frankenstein Meets the Wolf Man (1943) We need a spoiler!
Son of Dracula (1943) We need a spoiler!
House of Frankenstein (1944) We need a spoiler!
House of Dracula (1945) We need a spoiler!
Shame on You (1954) We need a spoiler!
Frankestein [sic] el vampiro y compania (1962) We need a spoiler!