Boo!
3 seconds sound clip from the Bon Voyage, Charlie Brown movie soundboard.
You can hear this line at 00:02:22 in the Blu-ray version of the movie.
Quote context
[...]
- Babette and Jacques will be spending two weeks here in America.
- What's he talking about? Who's going to France?
- The two students from our school who have been chosen are Charlie Brown and myself.
- Boo!
- We have accepted this great honor.
- We have?
[...]