The Dukes of Hazzard S07 E03 Dr. Jekyll and Mr. Duke

"You're in Hazzard County where the lawmen are crooks, the good guys are outlaws and ever'body's in-laws!"

Luke drinks some pond water that a truck accidentally spilled some genetic drugs into. This makes Luke character change a great deal. He becomes a total jerk, badmouths Bo, Daisy, and Jesse, harasses every girl at the Boar's Nest and eventually plans to rob Boss' bank.