Jon Hamm is Don Grouper in the trailer for SpongeBob’s Mad Men parody episode

Ever the money-hungry businessman, Mr. Krabs is expanding his burger empire with the help of Jon Hamm’s ad man. As we reported last September, Hamm guest stars in SpongeBob SquarePants’ “Goodbye, Krabby Patty?” as Don Grouper of the Grouper, Goby & Koi ad agency, mastermind behind the Krusty Krab’s expansion into the…