In my novel The Hidden Monastery I used a fox spirit as the antagonist in the story.

These pesky creatures can morph into humans. Here are some foxy tales.

In China there are many tales about Hu Li Jing or Fox Spirits. It is said that they acquired shape-shifting qualities after meditating in mountain caves for centuries. This allowed them to take on human form, the most common of which was that of beautiful young women. They would seduce men, because the ‘yang’ or light energy carried by men would complement the ‘yin’ or dark energy carried by these fox spirits and combine to give them immortality. Fox Spirits often have 9 tails.
There are other stories of fox spirits whose only desire is to experience human emotions such as love and happiness.

The Japanese Fox Spirit or Kitsune also has many tails, the more tails a fox has, the older and more powerful it is. They could grow up to nine tails after having lived a thousand years. In some tales, kitsune were able to take on the appearance of humans, but they would have trouble disguising their tails and often be discovered, especially by suspicious dogs, their mortal enemies.

In Finland, the northern lights was believed to be the result of a fox running on the snow and sweeping its tail so that sparks fly off into the sky. The aurora borealis was also known as Fox Fires.

Strange Tales of Liaozhai written in 1765 by Pu Songling is a much loved Chinese classic. These supernatural folk tales fall into three categories. Some were written to criticize the feudal society of Pu’s time, some to expose the malpractices of the imperial examination system, while others show his dissatisfaction to arranged marriages. He felt that people should marry for love. Pu Songling was a man ahead of his time in China.