I am the terror that flaps in the night.
3 seconds sound clip from the Darkwing Duck - Darkly Dawns the Duck: Part 1 (S01E01) movie soundboard.
You can hear this line at 00:08:01.014 in the DVD version of the TV Series.
Quote context
[...]
- Hey, wait! Oh, you can't go in there. That's top secret.
- No worry. Just checking out an unauthorized bird-boarding.
- It's Hoof and Mouth. They work for Taurus Bulba. Bulba's as big as they come!
- This is it: my shot at big-time crime-busting... what Darkwing Duck was born for.
- I am the terror that flaps in the night.
- I am the switch that derails your train.
- You think he's dead? I think he's dead. You think he's dead? He must be dead.
- Sorry. I'm fine. But you two are taking a turn for the worse.
[...]