Starring: Dee Bradley Baker, Mae Whitman, Jack De Sena, Zach Tyler
The Desert - S2-E11
Other mistake: At the start, when Toph says, "I can hardly feel any vibrations out here," Aang moves his head, and it briefly duplicates. Right after that, Aang seems to shift into another position without any animation, most noticeable with his head and face. (00:01:56)
The Library - S2-E10
Trivia: Wan Shi Tong is of one the few things in this show that is not a reference to Asian cultures, but to Ancient Greece instead. In their mythology owls were the symbol of wisdom and their goddess of wisdom, Athena, was often depicted with an owl.
Chosen answer: Toph had Katara use it to send a letter to her parents. It never returned.