During the first meeting between Aang and Bumi, in the background you can see statues of Flopsy, Bumi's pet from the animated series.
This episode combines elements from multiple episodes from the animated series: The King of Omashu (S1E5), Winter Solstice Part 1 The Spirit World (S1E7), Jet (S1E10), The Northern Air Temple (S1E17), The Cave of the Two Lovers (S2E2), Zuko Alone (S2E7), and The Tales of Ba Sing Se (S2E15).