Good boy, Scooby! Back him up just a little more! Now!
4 seconds sound clip from Scooby-Doo, Where Are You! - A Gaggle of Galloping Ghosts (S1E11).
You can hear this line at 00:07:07.493 in the Blu-ray version of the episode.
Quote context
[...]
- Time for a little ventriloquism.
- Where you going, fuzzy face?
- You must be the big bad wolf!
- Good boy, Scooby! Back him up just a little more! Now!
- That's just how I planned it. Now, get me down!
- Jump!
- Whee!
- Hurry! He's trying to get loose.
- I wonder where Shaggy and Scooby could be.
- I don't know, but let's check out that room up ahead.
- Look at that fire! Maybe we're expected for dinner.
- Fine, as long as we're not the dinner.
[...]