The Trolls are small creatures who live in an almost perpetual state of happiness, singing, dancing and hugging all day long. However, they are discovered by the Bergens, large creatures who never feel happy but discover that they can feel happy for a moment if they eat a Troll. The Bergens put the Trolls and their tree in a cage, and hold an annual festival in which each Bergen gets its feeling of happiness by eating a Troll. However, the Trolls, led by their King Peppy (Jeffrey Tambor), escape through underground tunnels on the day that the Bergen crown prince Gristle Jr. (Christopher Mintz-Plasse) would taste his first Troll. The furious Bergen King Gristle Sr. (John Cleese) banishes the Chef (Christine Baranski) who was in charge of the Troll preparation.