When Aang, Katara, and Sokka visited Omashu to do some sightseeing, the Avatar brought his friends on a ride down the city's delivery system. After the cart had fallen off the rails and ruined countless buildings, a bearded cat jumped into Aang's wig which he had been using as a disguise, where the animal encountered Momo. The two animals fought with each other for a moment before the lemur pushed it out of the cart.
Aang later met another cat named Miyuki who was owned by a herbalist in the city of Taku, and who was boasted by her owner to have grown to ninety-seven in human years. Miyuki was alongside the herbalist when Zuko, Iroh, and June were led to the institute by Nyla, June's shirshu.
Fluffykins was a cat who resided in Ba Sing Se with a family. When Aang created a new zoo with his bending to replace the old, inhospitable one, Kenji, the zookeeper, complimented the Avatar on his accomplishment and suggested that he make a career for himself working with animals. Kenji quickly retracted this opinion, however, when he overheard a few people, including Fluffykins' owners, finding their pets who had been mistakenly put in the zoo, as well. There was also a chubby white cat standing behind Fluffykins and next to a brown-furred dog, but it went unnamed.
In the Fire Nation, a cat stood and watched a woman hang her laundry on a clothesline.
Cats are relatively small in comparison to other animals, and they vary greatly in type and color. Certain attributes that differ among cats are fur length and color, eye color, and body shape. For example, bearded cats are set apart by shorter fur and their long, white muzzle fur, taking the appearance of a beard.
Only domesticated cats are known to exist. The bearded cat was hostile, although this may have only been because it felt provoked by Momo. Miyuki was calm in all situations, and Fluffykins did not have enough personality development to be distinguished, the same situation being for the unnamed white cat in the zoo and a likewise white cat of the Fire Nation.
Every trait and outward appearance of cats in the series point to the idea that they are based simply on real-world domesticated house-cats.
- There are two known animals with which the cat has been hybridized: with the owl to form the cat owl, and with the deer to form the cat deer. The cat owl has been seen in the wild as well as domesticated, unlike the cat, which has only been seen as a pet. About the cat deer little is known except that it is a prehistoric creature that was, like the cat owl, capable of being wild and domesticated.