One of them's a coffin containing the remains of the original Count Dracula.
6 seconds sound clip from the Abbott & Costello Meet Frankenstein movie soundboard.
You can hear this line at 00:06:58 in the Blu-ray version of the movie.
Quote context
[...]
- He's busy, he's busy. Please.
- That little fellow's impossible.
- Do you know what I've got in there, miss? Haven't the slightest idea.
- Just the greatest attraction the House of Horrors ever had, that's all.
- One of them's a coffin containing the remains of the original Count Dracula.
- And the other's the body of the Frankenstein Monster.
- Guess that combination's enough to scare the pants... I mean, shirt right off your back, ain't it?
- Neither do I, where money's concerned.
- I got 'em dirt cheap. European agent picked my name right out of thin air.
[...]