Katara(Mae Whitman) A waterbender in training until she mastered later in the show. She is 14 and finds Aang in the iceberg which frees him at last in 100 years. She has a brother named Sokka,And has a strong relationship with her mother which was killed by The Fire Nation, She is later Aang's love intrest. Her orignal name is Kya in the unaired pilot episode, Until her mother took the name.
Aang(Zachery Tyler) A airbender and the avatar in training until he mastered four elements in the show. He is 112 and sometimes considered 12. He was found by Katara and Sokka after his 100 year absence. He is a goofy, Extraordinary kid.
Sokka(Jack DeSena) A non-bender warrior of The Water Tribe, He is 15 and has a close relationship with his dad, He is a overprotective brother of Katara because of the promise of his dad to protect the tribe, He is a joker and always wants to eat as seen in many episodes, He has a relationship with Suki in book 2.
Toph Beifong(Jessie Flower) A blind earthbender who is disturbed by her over-protective parents, She later joins team avatar and teaches earthbending. She is 12 years old, She can see with feeling the earth with her feet to sense stuff.
Zuko(Dante Basco) A banished prince from The Fire Nation and firebender, He hunts Aang down then later joins him to stop the Firelord. He is 16, He has a sister named Azula who is currently his enemy.