Black Tortoise, Fresco from a tomb in Kangso, South Pchjongan Province, Koguryo state, North Korea. 6th - 7th century. The Black Tortoise is one of the Four Symbols of the Chinese constellations. It is known as Hyeonmu in Korean. It represents the north and the winter season. Although its name in Chinese is often translated as Black Tortoise in English, it is usually depicted as both a tortoise and a snake, with the snake coiling around the tortoise.