That's a real cracker!

Meaning

That's a very funny or amusing story/joke.

Examples

• John: Did I ever tell you about the time I met a kangaroo?
• Alice: No! Tell me!
• John: Well, it was hilarious! <b>That's a real cracker</b>!
• Alice: Oh my god, I'm dying! Yes, definitely <b>that's a real cracker</b>!