Counting the episodes where they do not have any lines, the most prominent characters of the show are Aang, Katara, and Sokka, who appear in every episode of the series except episode 27, "Zuko Alone" (although Aang's spiritless body can be seen during the "Previously, on Avatar..." introduction). The second place belongs to Momo, who appears in 56 episodes, followed by Appa with 54, Zuko with 48, Iroh with 39, and Toph with 36 episodes. The most infrequent recurring character is Azula, who appears in 22 episodes.
The design of the white lotus tile changes through the course of the series :
All episodes that were grouped as specials/movies when they first aired, were aired separately in subsequent airings.