You better cut it out right now or I'll pound you!
3 seconds sound clip from the It's the Great Pumpkin, Charlie Brown (1966) movie soundboard.
You can hear this line at 00:05:39.610 in the Blu-ray version of the movie.
Quote context
[...]
- We are obviously separated by denominational differences.
- Not again? Writing a letter to a stupid pumpkin?
- You make me the laughingstock of the neighborhood!
- All they talk about is my little brother who always writes to the Great Pumpkin.
- You better cut it out right now or I'll pound you!
- You're wasting your time! The Great Pumpkin is a fake!
- I'd rather not say. You might laugh.
[...]