Now, Mr. Hannigan here claims to have known your grandfather.
4 seconds sound clip from the Darkwing Duck - Darkly Dawns the Duck: Part 1 (S01E01) movie soundboard.
You can hear this line at 00:15:29.871 in the DVD version of the TV Series.
Quote context
[...]
- Sorry, Mrs. Cavanaugh. I'm in the middle of a game. Can't chat now.
- Look, I don't know anything about a pig, and I was nowhere near the boys' bathroom at the time.
- Pig? I meant big. As in how big of you to take such an interest in me. How may I help you?
- Now, Mr. Hannigan here claims to have known your grandfather.
- Aw, sure. That's me in the background.
- Actually, it looks like a grape jelly stain.
- Why don't we take a walk? We can swap stories about your granddad.
- Well, I suppose it would be all right, as long as you stay on the orphanage grounds.
[...]