Many ancient cultures have stories about dragons at the center of their mythologies. Here we focus on those of India and China.
Long before there was a Chinese nation, tribes roamed the land, each with their own story of creation. Some of these stories have lasted to the modern day, being incorporated into different Buddhist mythologies. One of these tales is called "Pan Gu and the cosmic egg."
First was chaos. Out of it formed a cosmic egg in which yin and yang were combined. Inside, Pan Gu, the creator, grew for eighteen thousand years. When finally he awoke, he broke the cosmic egg in half. The top half, yang, floated up and became the heavens. The bottom half, yin, sunk down and became the earth.
In between was Pan Gu, a great dragon. And for the next eighteen thousand years he set about the task of forming all in existence.
Helping him were his four companions, Fen Huang, the phoenix, Lung Wang, the dragon, Qi Lin, the unicorn, and Gui Xian, the turtle. These were the Ssu-ling, and were the guardians of the four cardinal directions, the elements, and the seasons. The dragon guards the east, the phoenix the south, the unicorn the west, and the turtle north.
When Pan Gu died, his body dispersed. His two eyes became the sun and moon, his last breath became the wind, his body became the mountains and plains, rivers flowed from his bloods, his sweat became the rain, and the fleas on his fur became the creatures of existence, from the smallest flea, to the largest whale.
His four friends became of more importance with the great dragon gone. They were the protectors of nature. The phoenix flew into the sky with the winged creatures, the unicorn ran into the forest to protect the beasts, the turtle slunk into the marshes, and the dragon dove into the water, the blood of the creator.
In India there is the three-headed Vritra, a dragon who wrapped himself about the world and drank all of the waters.
Vritra was an asura, an evil creature that stood in opposition to the devas, or gods.
Indra, the king of the gods, drank massive quantities of Soma, the Indian version of ambrosia, and took a thunderbolt made by tvastar the architect of creation, to prepare to slay Vritra and free the water.
I will declare the manly deeds of Indra, the first that he achieved, the Thunder-wielder.
He slew the Dragon, then disclosed the waters, and cleft the channels of the mountain torrents.
He slew the Dragon lying on the mountain: his heavenly bolt of thunder Tvastar fashioned. (from the Rig Veda)
So, Indra returned water to mankind and the world.
It is interesting to note that, considering the time it was written, and the spread of Indian culture, it is likely this is the precursor to the European epic legends of dragons.