The Amazing World of Gumball Season 3 Episode 20 The Shell Episode Title:The Shell.Episode Description:After accidentally headbutting her during a school play and causing a crack to form (which lands him in trouble with Penny's father), Gumball urges Penny to break from her shell and reveal her true form. However, when Gumball is left speechless by her beauty, Penny misinterprets his shock as disappointment and goes on a rampage through Elmore, shapeshifting into several monsters. Evantually, Gumball is able to tell his true feelings to Penny by kissing her and restores, making them an official couple.