Aang was the Avatar after Roku and before Korra.
Aang was trapped in an iceberg for a hundred years. When he was awakened, he teamed up with Katara and Sonng to learn his other Bending. He was opposed by the Fire Nation, who had sent out a war on the rest of the world. His finally destiny was to destroy the Fire Lord and being peace to the world. The new Fire Lord Zuko and him made the Republic of Nations, the capital Republic City. He came back in spirit form to help Korra after she got her bending taken away from her by Amon.
Aang had all four elemental powers. He had to learn Waterbending, Earthbending, Firebending, and Evergybending with his friends. He became one of the best Avatars in history.
Aang is very nice. He loves to be nice to his friends. His attitude changes very much whenever he is in the Avatar State.
Aang has the cutomary Airbender tattoos. He has no hair, which is also customary. He has the regular Airbender robes.