For the last century, Appa and Aang had been frozen in a ball of ice, which makes them each the last of their kind. Once unfrozen, he served as transport for Team Avatar.
Appa is displayed in The Last Airbender by computer animation and special effects. There are several differences between the appearance of Appa in the television show and that of Appa in the movie. The differences include the shape of his horns, head, muzzle, face, legs, and his size.
Appa appears much less in the film than his animated counterpart did in the series. This was due to the difficultly of bringing Appa to life; while he was easily created in the cartoon version, in the film the animators found it hard to make Appa look realistic.
Appa's stripe pattern is different in the movie compared to the series.
Dee Bradley Baker, the voice actor who provides all the animal voices in the show, reprises his role as Appa in the film.