Xuanwu is a mythical beast imagined by ancient people in China, and it is a combination of two animals.

Xuanwu is a spiritual thing composed of turtles and snakes. Xuanwu originally meant Xuanming, and the ancient sounds of Wu and Ming are interlinked. Xuan means black; Ghost means yin. At first, Xuan Ming described the tortoise's divination as follows: the tortoise's back is black, and the tortoise's divination is to invite the tortoise to the underworld to ask questions, bring back the answers and show them to the world in the form of divination. Therefore, the earliest Xuanwu is the tortoise. Since then, the meaning of Xuanming has been expanding. Turtles live in rivers, lakes and seas (including turtles), so Xuan Ming became a water god; The tortoise lives long, and Xuan Ming has become a symbol of immortality; It turned out that the underworld was in the north, and the divination of Oracle Bone Inscriptions in Shang Dynasty was' its divination will be in the north', so Xuan Ming became a northern god again.

Xuanwu, like other three spirits, is also derived from the 28 stars on earth: bucket, ox, female, air, danger, house and wall. In ancient times, people explained Xuanwu in this way. Xuanwu' is a tortoise. "Book of Rites. "Quli Shang" says:' Zhu bird before departure, then Xuanwu ...'' Xuanwu' is a tortoise and snake. Supplementary Notes on Hong Xingzu's Songs of the South. Travel far:' Xuanwu is called tortoise and snake. Located in the north, it is called Xuan. With a scale, it is called martial arts. Xuanwu is a combination of snakes, turtles and snakes.