The turtle (gui 龜) is an auspicious animal in ancient Chinese mythology.
It is said in the book Zhongxuanji 中玄記 that a thousand years-old turtle eas able to communicate with humans. The book the Shuyiji 述異記 adds that in the age of one thousand years a turtle grows hair. A five thousand years-old turtle was called shengui 神龜 "divine turtle", and an animal older than ten thousand years linggui 靈龜 "spiritual turtle".
The black turtle xuangui 玄龜, wugui 烏龜 or xuanwu 玄武, or "turtle-snake" guishe 龜蛇 was the symbol of the north, darkness and winter.