Couple of lines in the space of a few seconds in one episode where Bart & Lisa are put in the same class:
Hillbilly: Say your prayers
Bart: Oh Lord, please strike these mountain folk dead
Hillbilly: ....I married a bear, and I started up a family
Hillbilly's wife: I told you I ain't a bear
Hillbilly: Roar roar roar, no-one understands you she-bear