Avatar: The Last Airbender - Into The Inferno (DS)
Go to the Ember Island menu. Select "Enter Code", then enter one of the following passwords to have that character appear at the Volleyball Theater.
Enter Momo, Sokka, Toph as a password.
Enter Pakku, Iroh, Appa as a password.
Enter Aang, Katara, Zuko as a password.