Hēidì () or Hēishén (), who is the Běidì (, Cantonese: Pak Tai) or Běiyuèdàdì () is a deity in Chinese religion, one of the cosmological "Five Forms of the Highest Deity" (). He is also identified as Zhuānxū (), today frequently worshipped as Xuánwǔ () or Zhēnwǔ (), and is associated with the essence of water and winter. His animal form is the Black Dragon and his stellar animal is the tortoise-snake. By virtue of his association with the north he has been identified and revered frequently as a representation of the supreme God of Heaven. Taoist myths involving the Black Deity A Taoist title of Heidi is the "Dark (or Mysterious) Heavenly Highest Deity" (). According to a myth, during the fall of the Shang the Demon King ravaged the world, so that Yuanshi Tianzun ordered the Jade Emperor to appoint Heidi as the commander of twelve heavenly legions to fight this evil. Heidi defeated the Demon King and was subsequently granted the title of Mysterious Heavenly Highest Deity. In temples dedicated to him, the bronze tortoise and serpent under the feet of his image signify that the good always prevails over evil. Festivals The day for celebration of Heidi across China is his birthday on lunar April 21. A festival is held on the island of Taipa in Macau. The celebration at the Pak Tai Temple includes an opera-styled performance Annual Bun Festival in Cheung Chau Island, Hong Kong, held in front of the Pak Tai Temple. Temples in Hong Kong In Hong Kong, it is worshipped among other places in: See also Xuántiān Shàngdì Chinese mythology Bok Kai Temple (California, USA) References Sources External links Chinese gods Mercurian deities Wufang Shangdi