Watch this. Grr!
5 seconds sound clip from Scooby-Doo, Where Are You! - The Backstage Rag (S1E9).
You can hear this line at 00:13:07.645 in the Blu-ray version of the episode.
Quote context
[...]
- What's with you, Scooby Doo?
- Aww! Ha ha ha! It's only a jack-in-the-box.
- Huh? Aww! Yeah! Hee hee hee!
- Now, stop clowning around and keep looking.
- Right.
- Hey, Scooby, check this. Pretty heroic, huh?
- Ha ha ha! That's great! Hold it a sec. Aha! The Cloaked Cavalier!
- That's a doozie! Hee hee hee! Huh?
- Uh-oh. There were rwo of you.
- There were two of me? I don't get it, Scoob. Huh?
- You saw somebody else dressed like me?
- I wish I knew what we were looking for.
[...]