6x18 - The Grim Adventures of Billy and Mandy

As Mandy returns from Billy's house, it is evident that Mandy's parents are extremely afraid of their daughter and her iron fist rule over them. Unable to live in fear any longer, Mandy's parents call a nanny from a reality TV show who specializes in disciplining spoiled children. Mandy and the nanny clash while the nanny tries to teach Mandy's parents to show authority to control their daughter. Grim helps the nanny in her feud against Mandy by using his scythe to make Mandy's parents more controlling and resolute. Mandy quickly restores her tyrannic control over her parents, and shows the nanny she actually controls everything and everyone.