Avatar the Last Airbender , Book 1 episode 14 - The Fortuneteller .
If you mean the part where Katara is explaining what happend in the war and what Aang is trying to do as the avatar the answer is that it isn't from any episode, but if you mean the part when it's like "previously on Avatar" it depends on what episode your watching it can be from any episode.
In Book 2 Chapter 10 "The Library".
Avatar: The Last Airbender was not based on a book.
She voiced Ming in the "Day of the Black Sun" episode .
Avatar the Last Airbender , Book 1 episode 14 - The Fortuneteller .
Book 3 Episode 8
"The Headband"
Episode 27/61
Episode # 48 : "The Puppetmaster"
no its ended but they are planning on making Avatar The Legend of Korra
Episode 13 : "The Blue Spirit" .
its the first episode in the second chapter (Earth)
bato of the water tribe
November 12. 2007 is when the last episode aired.
Aang is the current avatar. He is aslo The Last Airbender as says the title. Anyone who say at least one episode would realize this.
Book two, ( Season two), episode 19, " The Guru"