- They got him! But what's going on?
- Simple! He hypnotized himself!

7 seconds sound clip from Scooby-Doo, Where Are You! - Bedlam in the Big Top (S1E10).

You can hear this line at 00:19:30.111 in the Blu-ray version of the episode.

Quote context

[...]

- I have an idea about this ghost, Scooby, and we're going out again.

- Not again!

- Ha ha ha ha! Watch the pretty coin of gold, and you both shall do as you are told.

- Now, Scooby!

- You both have fur. You both are limp. You swing from trees like a happy chimp. Watch the pretty coin of gold. Be chimpanzees as you are told!

- Look what Shaggy and Scooby brought in on a leash.

- They got him! But what's going on?

- Simple! He hypnotized himself!

- I know that man. He's Harry the Hypnotist.

- He had an act with us, but we caught him stealing and sent him to prison.

- Looks like he wanted to get revenge.

- As a ghost clown, he knew he could ruin your circus.

[...]