The Apprentice / The Pest

S4, E201: Gumball decides that the best way to prove to Mr. Fitzgerald that he's good enough for Penny is to become his apprentice for the day. The problem is, Mr. Fitzgerald has an important interview and Gumball's enthusiastic attempts to help him might actually do more harm than good, both to Mr. Fitzgerald's business and to Gumball's future with Penny./When they find Anais training herself for a brutal showdown, Gumball and Darwin realise that their sister is being pestered at school by an annoying kid: Billy. They try to teach her how to resolve the problem peacefully, but Billy has other ideas.