Avatar: The Last Airbender Season 2 Episode 12 : The Serpent's Pass
After leaving the desert, the group meets up with Suki, and attempts to lead a couple through the Serpent's Pass. They are attacked by a giant serpent, but ward it off and make it across. Meanwhile, Zuko and Iroh are also on their way to start a new life in the Earth Kingdom capital of Ba Sing Se, and encounter Jet and some of the Freedom Fighters, with whom Zuko starts to bond. The group finally makes it to Ba Sing Se only to find the Fire Nation is about to send a gigantic drill to destroy the city's wall.