Why did the ghost go to the dance party?

Because he heard it was a real scream

What did the skeleton say when his friend asked to borrow some money?

You're always draining my resources.

Why did the Creature from the Black Lagoon go to the post office?

Because it wanted to send a scaled-up package

Why did Frankenstein's monster get kicked out of the library?

Because he kept reanimating the classics.