He's the one who's causing all the trouble.
2 seconds sound clip from the Rock-a-Doodle movie soundboard.
You can hear this line at 00:06:16.603 in the Blu-ray version of the movie.
Quote context
[...]
- Hey, everybody, cock-a-doodle-doo!
- The Grand Duke's evil plan had worked. He had turned us against our very best friend.
- And without a reason to crow, poor Chanticleer left the farm to look for work in the city.
- Then came the rain, and our troubles with the Duke.
- He's the one who's causing all the trouble.
- He sent that mean old rooster to Chanticleer's farm to pick a fight.
- Because he didn't like Chanticleer doing all that crowing, and bringing up the sun.
- Well, like most owls, he likes the darkness and the rain.
- Oh, it's you. You scared me!
[...]