Prior to the Hundred Year War, many flying bison lived in the air temples. They were highly respected by the Air Nomads, who regarded them as the first airbenders. While airbenders were in training, they each received a flying bison to become their lifelong companion. The sky bison was believed to be the only way in which people could reach an air temple.
After the Air Nomad Genocide, Appa was believed to be the last of the flying bison. However, during his adventures after the Hundred Year War, Aang discovered a new herd, and the population started to grow again with colonies of healthy bison residing at all of the air temples.
When Ikki ran away while visiting the Southern Air Temple in 171 AG, she hid in a cave that a bison family had made their home. While both parents were out, the young airbender entertained the four calves whom she had named Blueberry Spicehead, Princess Rainbow, Twinkle Starchild, and Juniper Lightning Bug. When Tenzin eventually found his daughter, he joined her in the cave, bonding particularly with Blueberry Spicehead.
After Korra reconnected with her Avatar Spirit, she was given a flying bison from a herd that an elderly female shaman and other Fire Sages had been raising since the end of the Hundred Year War. The Avatar used the bison to return to the Southern Water Tribe in preparation for the upcoming Harmonic Convergence.
Flying bison have five stomachs, flat manatee-like tails, brown eyes, shaggy white fur, and a brown stripe that runs along their back from tail-tip to forehead, where it terminates in an arrowhead. They have six legs with three toes on each foot. As they are primarily herbivores, flying bison have flat teeth shaped like peanuts, which are spread out on the roof and bottom of the mouth in groups of ten. A fully-grown flying bison can easily weigh ten tons. They are revered by the Air Nomads for inspiring the art of airbending; the tattoos of an airbending master deliberately imitate the arrow-shaped markings of the bison.
The species Aang rediscovered after the Hundred Year War has a slightly different fur pattern with multiple brown stripes running down their backs, as well as brown ears instead of white.
All flying bison employ airbending to fly, using their wide tails to steer through air currents and to defend themselves from attacks. They are also able to use their mouths to airbend. Though fairly docile, flying bison can be fierce and powerful opponents if pressed or enraged, possessing great physical strength and airbending skills, as Appa demonstrated on several occasions. These creatures were the main means of transportation for Air Nomads. It was customary for young Air Nomads to choose a flying bison to be their lifelong companion. Aang chose Appa at the Eastern Air Temple when he was a young child by giving him an apple. At the Northern Air Temple, airbenders held championships for bison polo. This game was played in the air; as airbenders rode their bison, they tried to force the ball with their polo mallet into an opponent's goal. To command their bison to take flight, both Aang and Tenzin use the command "yip-yip". To summon a bison from a distant location, it is possible to use a bison whistle. A sky bison whistle emits a sound at a frequency that is near or completely inaudible to humans, but can be heard clearly by bison.
Notable flying bison
The flying bison is a hybrid between a bison and a manatee. The real-life bison shares a similar history to the flying bison, in that they were a very abundant species until foreigners came and hunted them down, reducing their numbers to near-extinction. Both have also been commonly misidentified as a buffalo.
- The circus master called Appa a "Wind Buffalo" for his circus act.
- During San Diego Comic-Con, it was revealed that Avatar Aang had discovered a whole new herd of sky bison. The new subspecies has a few differences; for example: old bison had four transversal stripes plus the last one that lies at the end of the tail, whereas the new species has more stripes that are thinner. The new bison also have brown fur on their ears instead of white.
- The movement animation of the flying bison was heavily influenced by the similarly-shaped multi-legged Catbus in Hayao Miyazaki's movie My Neighbor Totoro. The series' creators have professed their love of Miyazaki's work in many interviews.
- In the book Avatar: The Last Airbender — The Art of the Animated Series, it is shown that the original design of flying bison more closely resembled sea manatees.
- According to Avatar Extras, sky bison are the world's loudest snorers, with airbenders being second.
- In Avatar Korra's time, the new species of sky bison that reside on Air Temple Island live in a series of caves. However, Aang's sky bison, Appa, had a fear of going in caves, meaning that Appa's phobia was a personal trait rather than a behavioral trait in the species.
- Both flying bison and dragons have shown affection by licking people, similar to the way real world dogs do.