The creature Gong Gong, also known as Kung Kung, is a legendary figure in ancient Chinese myth. He was said to resemble an evil, monstrous dragon. He had a huge horn protruding from his forhead. Gong Gong was ferocious and power-hungry, and he wished to take control of the land. For this reason, Gong Gong waged a fierce battle against the ruler of the country, Chuan-Xu, the emperor.
In the end, Chuan-Xu outsmarted Gong Gong and won the war. Gong Gong, enraged by his loss, tried to destroy the world by tearing down the sky. So he angrily began to rip and tear apart the mountains which, as everyone in ancient China knew, held up the sky; however, being weak from his long battle with the emperor, Gong Gong was only able to do damage to Mount Pu Chou, the supporting mountain in the north-west. This caused a hole to be torn in the sky, and that region of the sky collapsed. Because of this, the sun, moon, and stars slipped toward the north-west; also, the earth tilted to the south-east, causing the waters to flow toward that direction.
As for the hole in the sky, the first long, or dragon, appeared to the mythological emperor Fu Xi, filling up the hole left by Gong Gong.
Gong Gong represents the eternal opponent of the emperor; he is also thought to be responsible for great floods. Gong Gong is often depicted with and/or related to Xiang Yao, a snake-like entity.
http://www-k12.atmos.washington.edu/k12/modules/nw_wx_watch/kungkung.html
http://www.pantheon.org/articles/g/gong_gong.html
http://www.mythopedia.info/20-china.htm