In this way the east was the azure dragon, the south the vermilion bird, west the white tiger and north the sombre warrior.
The Tortoise belonging to the Yin principle was regarded as feminine, and Chinese legend associates it with the serpent in much the same way that the serpent is related to the feminine principle in nearly all primitive myths and legends. Associated thus the Serpent and Tortoise when depicted together are called the "Dark Warriors" and typify the north.
"Cloud follows the dragon, Wind follows the tiger."
The symbolism of the Dragon and the Tiger is of great antiquity preceding that of Yang and Yin although the idea conveyed is the same. The Dragon typified heaven, the sky, fertility, the Tiger, chief of all land animals the earth. Their union expressed that belief so old and so persistently held that perfect bliss and happiness are only attained when the dualistic forces are in equilibrium. Without the earth heaven would have no way of expressing itself. The earth, unless revivified by heaven, would be only a cold, dark, inert mass, the region of death and decay.
The dragon and tiger also symbolised the two constellations Scorpio and Orion.
The Bird and Tortoise, emblems respectively of Yang, summer, and Yin, winter only appear after the dragon and tiger.