Princess Azula is the secondary antagonist of Avatar: The Last Airbender. She first appears as a cameo character at the end of Book 1 Water and would since then go on to serve as the main villainess of Book 2 Earth and as the secondary villainess of Book 3 Fire. She is the younger sister of Zuko, the granddaughter of Azulon and Ilah, the niece of Iroh, the infamous paternal aunt of Zuko's daughter Izumi, the maternal grandaunt of General Iron, and the daughter of Ozai who desires to succeed her father as fire lord.