The Southern Air Temple - S1-E3
Other mistake: When the gang is in the Hall of Statues of Past Avatars, Katara points out the avatar cycle pattern of statues and Aang zeroes in on Roku's statue. The earthbender avatar statue next to Roku is of an unknown man with a sword, not Kiyoshi. (00:12:50 - 00:13:35)
Other mistake: It appears as if Steve is holding 3 $20 bills when he supposedly received $50.
Other mistake: In the voice cast list, the Groom's Father appears twice - with two different voice actors - and the Groom's Mother is not even listed.
Tsuinzu gâdo - S1-E5
Other mistake: Van transfers the bunch of condiments from the cart to the table. Amongst said condiments, a big jar of "MASTARD." (00:07:00)
Gopherville - S1-E1
Other mistake: In "Sock Safari", when Toopy finds a red thread, his left hand with his glove disappears instantly.