So, I don't know if you've watched Avatar: The Last Airbender at all, but I just want to let you know that all this talk about it has reminded me of one thing: Toph Beifong is a bad friend.
See: S02E16 - Appa's Lost Days
Then again Aang could have polished his Little Bill-looking forehead so like... Katara or Sokka could look at it and see where Appa was taken...