Miyuki was a white, fluffy cat, with long, thick fur and light green, almost gray, eyes. She was the beloved pet of the herbalist.
Aang met the herbalist while searching for medicinal herbs to cure Katara and Sokka. When the old woman had finished preparing the mixture she was working on, Aang tried to grab it to bring back to his sick friends, but was slapped on the fingers by the herbalist, who informed Aang that it was Miyuki's dinner. This special diet of herbs had kept Miyuki alive for over twenty-eight years.
Some time later, when the bounty hunter June and her shirshu, Nyla, picked up Katara's trail near Taku, the herbalist asked Miyuki whether she had "gotten in trouble with the Fire Nation again".