Bunbuku Chagama

Bunbuku Chagama (Japanese: ぶんぶく茶釜) is a Japanese folktale about a raccoon-dog, or tanuki, that uses its shapeshifting powers to reward its rescuer for his kindness.
Bunbuku Chagama roughly translates to "happiness bubbling over like a tea pot." The story tells of a poor man who finds a tanuki caught in a trap. Feeling sorry for the animal, he sets it free. That night, the tanuki comes to the poor man's house to thank him for his kindness. The tanuki transforms itself into a chagama and tells the man to sell him for money.
The man sells the tanuki-teapot to a monk, who takes it home and, after scrubbing it harshly, sets it over the fire to boil water. Unable to stand the heat, the tanuki teapot sprouts legs and, in its half-transformed state, makes a run for it.
The tanuki returns to the poor man with another idea. The man would set up a 'roadside attraction' (a little circus-like setup) and charge admission for people to see a teapot walking a tightrope. The plan works, and each gains something good from the other--the man is no longer poor and the tanuki has a new friend and home.
In a variant of the story, the tanuki-teapot does not run and returns to its transformed state. The shocked monk decides to leave the teapot as an offering to the poor temple where he lives, choosing not to use it for making tea again. The temple eventually becomes famous for its supposed dancing teapot.