Sister Iio was an Air Nomad nun, as well as the Mother Superior of the Eastern Air Temple during Aang's childhood. She was unaffected and cheerful, and her opinions were respected by those in her care.
In 6 BG, Iio guided a group of young Air Nomad children, including Aang, through the tradition of choosing a flying bison. Leading them to an open area, she gave each of the children an apple to lure a bison calf and advised them to choose carefully when picking out their bison, stating that "a sky bison [was] a companion for life."
Avatar: The Last Airbender
Book Two: Earth (土)
- 216. "Appa's Lost Days" (dream)
- She wore a beaded necklace with a brooch that was similar to the one Monk Gyatso used to wear and the one Aang wore at Fire Lord Zuko's coronation.
- Aside from Avatars Yangchen and Kyoshi, Iio was the only named female airbender to be seen in the first series.
- Her arrow tattoos marked her as an airbending master.
- She was said to never look older than a forty-five-year-old, though she was actually eighty-seven years old.
- She was known to be good at playing airball.