I think I'm beginning to figure it out.
2 seconds sound clip from Scooby-Doo, Where Are You! - Hassle in the Castle (S1E3).
You can hear this line at 00:12:26.229 in the Blu-ray version of the episode.
Quote context
[...]
- Would you do it for a Scooby Snack? How about two?
- Three?
- But what's all this magic stuff doing here?
- I think I'm beginning to figure it out.
- Shh! Somebody's coming! Quick! Into the closet! Hurry!
- Whoever it was must've gone away.
- I warned you to leave the island! Now you will pay!
[...]