Avatar: The Last Airbender: Season 1, Episode 5

1 - 5: The King of Omashu

Aang takes Katara and Sokka back to a favorite place he used to go to when he was younger, the Earth Kingdom City of Omashu. But when they break the law they are taken to the King to get their punishment. The eccentric King of Omashu puts Aang through a series of challenges and if he fails Katara and Sokka will be engulfed in a crystal cocoon.