Celestial Avatar Spirit Aang

The Celestial Avatar Spirit Aang is the symbol of Aang's Mastery over the Avatar State. Aang first encounters his enormous self while trying to open the Seventh Chakra in The Guru, but he abandons the State when he had a vision of Katara in trouble. He again encounters this in The Crossroads of Destiny while fighting Azula and Zuko. He was already able to release the Chakra when Azula zaps him with lightning. In both cases Aang was unable to clear the Chakra and master the Avatar State.

During the Sozin's Comet, Part 4: Avatar Aang, when Aang was knocked by Ozai to a rock and the Avatar State has activated, the same colossal figure mage up of pure Cosmic Energy was seen.