In Avatar: The Last Airbender, Aang’s lovable and fiercely loyal sky bison, Appa, has a distinct design including six legs, a flat tail, horns, and massive size. The early concept of a large fictional creature who acted as a companion for Aang remained the same, but Appa's specific design changed many times before the showrunners settled on the version that fans know and love. One of the earliest designs for Appa was a dog-like creature that eventually became the inspiration for Naga, Korra’s polar bear dog in Avatar: The Legend of Korra. Later designs for Appa included spiral horns, but the showrunners realized that the shape would be too difficult to animate.
Appa’s appearance had several inspirations, including two real-life creatures: manatees and buffalo. Appa has the nose and horns of a buffalo plus the rounded body and oblong tail of a manatee - an animal loved by Avatar: The Last Airbender co-creator, Bryan Konietzko. Manatees are large marine mammals, also known as sea cows. These herbivores are gentle giants and the way Appa moves through the air resembles the way a manatee moves through the water. But neither of these animals’ appearance’s explains the fact that Appa has six cat-like legs.
In the book, Avatar: The Last Airbender – The Art of the Animated Series, Konietzko reveals that Appa’s design was partially inspired by the Catbus in Hayao Miyazaki’s My Neighbor Totoro. The resemblance is so subtle that even fans of both Avatar and Totoro might not immediately draw a comparison between Catbus and Appa – the only obvious traits they share are their large size, ability to fly, and excess of appendages. The two characters are different in almost every other way.
In My Neighbor Totoro, the Catbus is summoned by Totoro to help Satsuki find her younger sister, Mei. Catbus, as the name implies, is a bus in the shape of a massive cat, including windows and a door for passengers to enter. The Catbus pounces, zooms, flies, and lurches, which is a stark contrast to Appa’s slow and gentle gliding. Catbus has a Cheshire-like grin, orange fur, a long tail – and twelve legs, which is twice as many as Appa’s six, but Appa's aesthetic pays direct homage to Hayao Miyazaki’s fourth feature film, My Neighbor Totoro.
Those who are familiar with Miyazaki’s work will likely notice other influences that the legendary filmmaker had on the Avatar series, particularly the stylized animation, nuanced characters, and epic storytelling sprinkled with vignettes of everyday life. The creators of Avatar - Michael Dante DiMartino and Bryan Konietzko - have both expressed their admiration for the incomparable Japanese filmmaker, Hayao Miyazaki, so it’s not surprising that they would want to honor his monumental work in Avatar: The Last Airbender through Appa. Appa and Catbus are both scene-stealing friendly giants, adored by audiences for their adorable, furry appearances and distinctive, lovable personalities.