What does it mean that there is a snake on the tortoise?

There is a snake on the turtle, which is the "Xuanwu", one of the four spirits in heaven in myth.

In ancient times, people thought that snakes were smart and good at collecting money, while turtles had hard armor on their ventral backs, and their heads, tails and limbs could be retracted into the armor, which made them hungry and thirsty, and their life span was very long. The worship of stars originated in ancient times refers to the fact that twenty-eight lodges in the four elephants are divided into seven lodges in the north Xuanwu according to the southeast and northwest, which also represents Zhuan Xu, one of the five emperors in Hei Di.

In the traditional culture of China, the four elephants refer to Qinglong, Baihu, Suzaku and Xuanwu, representing the east, west, north and south directions respectively. Xuanwu in the north is based on gossip, and the five elements dominate the water, symbolizing the old yin in the four elephants and the winter in the four seasons.

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Related legends

In ancient mythology of China, the four great beasts were Qinglong, Baihu, Suzaku and Xuanwu. Xuanwu, also called Xuanming, is a combination of tortoise and snake. It is the water god, living in Beihai, and the tortoise lives long. Xuan Ming has become a symbol of immortality, and the underworld is also in the north, so it is the god of the north.

On behalf of Zhuan Xu and the seven nights in the north, it is the northern god. Xuanwu is different from other three spirits because it can ask divination in the underworld. It is called the God of Tian Xuan and the "Zhenwu Emperor", and it is the god worshipped by Taoism.

Xuanwu was upgraded to the "Zhenwu Emperor" in the north by later Taoist priests. Different from the other three spirits. Other green dragons and white tigers only became the gatekeepers of the mountain temple, and Zhu Bird became the Xuan Nv of another day. It is often said by later generations that during the reign of Yang Di, the Jade Emperor became one of his three souls, Empress Lezheng, tired of the world, abandoned Wudang Mountain for practice, and successfully ascended to heaven, defended the north and lived in Xuanwu, posthumous title.

Baidu Encyclopedia-Xuanwu