"Water, Earth, Fire, Air...'Long ago the four nations lived together in peace and harmony. Then everything changed when the Fire Nation attacked. Only the Avatar, Master of all Four Elements, can stop the Fire Nation and bring balance to the world. But when the world needed him most...he vanished. A hundred years passed and my brother and I found the new Avatar, an Airbender named Aang. Although he's the Avatar, he still has alot to learn before he can save everyone. But I believe, Aang can save the world."
Katara narrating the opening of the series (Avatar: The Last Airbender)
Katara is a fictional character from Avatar: The Last Airbender. She's a waterbender, a sister to Sokka and daughter of Hakoda and Kya. She became a waterbendering master thanks to Pakku and aided Aang on his journey to bend the four elements and free the world from the threat of the Fire Nation.
In the fanfiction realm, she became Terrence's love interest and a member of the Majestic Guardians.