In Greek myth the founder of Athens was Cecrops, who was born of the earth (without parents), as a half-man, half-serpent - he had a tail from the waist down:
As the first king of Attica, Cecrops greatly contributed to the civilising of the state. He was the provider of laws, and encouraged monogamy. He invented writing, ended human sacrifices and encouraged a new practice of burying the dead. He called his principal city Cecropia but his people wanted the city to be associated with a god, either Poseidon or Athena. Poseidon demonstrated his power by striking his trident and cracking the rock of the Acropolis, causing a stream of water to flow out. Athena simply created an olive tree, which the people preferred, and so they designated her the patron deity - hence the city's modern name of Athens. Poseidon was greatly upset by his loss and punished Cecrops and the city by sending a disastrous flood. The people survived and built a new city of Athens.
There are further serpentine links to be found in these stories, as well as connections to floods:
Athena was the goddess of wisdom, prudent warfare, arts and crafts, and defender of the law. She taught the science of numbers, and she invented such things as the potter's wheel, flute, chariot, ship, and plough. To this day she is a patroness of art, science, and learning - not unlike Quetzalcoatl across the Atlantic.
Athena could not prevent Hephaestus (the god of fire and metal-working) falling in love with her, yet she wished to remain a virgin. Hephaestus pursued her and caught her on the Acropolis. He brushed up against her, spilling his seed. Athena wiped it off with a piece of cloth and threw it onto the ground, fertilising it. This produced Erichthonius, a boy with a serpents tail like Cecrops, who Athena decided to keep as her own son.
Children of the soil, such as Cecrops and Erichthonius were known as Autochthons, literally "sprung from the earth". They were said to have neither father nor mother, and therefore they just arose from the ground like a plant does. This race usually appeared during those periods in which the motion of the universe was reversed - caused by the withdrawal of divinity. Under such conditions, lacking a divine overseer, normal birth was not possible, so the people were born from the earth instead.
(Without a mother) from the teeming Earth;
Minerva nurs'd him, and the infant laid
Within a chest, of twining osiers made.
The daughters of king Cecrops undertook
To guard the chest, commanded not to look
On what was hid within. I stood to see
The charge obey'd, perch'd on a neighb'ring tree.
The sisters Pandrosos and Herse keep
The strict command; Aglauros needs would peep,
And saw the monstrous infant, in a fright,
And call'd her sisters to the hideous sight:
A boy's soft shape did to the waste prevail,
But the boy ended in a dragon's tail.
From Ovid's Metamorphoses
Aglauros and Herse went mad at the sight of him and hurled themselves from the top of the rocks of the Acropolis. Pandrosos, who had obeyed the rules, was made the first priestess of Athene. Athena then secretly looked after Erichthonius in her sanctuary while he grew up, and eventually he became the next King of Athens.
After the Flood of Deukalion, Zeus commanded Prometheus and Athena to call forth a new race of men from the mire left by the waters of the deluge.  Prometheus shaped men out of mud, and Athena breathed life into the clay figures. Also born of the mud was a great snake named Python who lived at the centre of the world, and held it together. Soon after it was killed by Apollo.
Wherever the Chinese New Year is observed, the dragon is the most prominent symbol. Long weaving dragons ride upon the shoulders of dozens of men, undulating through streets crowded with festive onlookers. Apart from festivities, dragons dominate the architecture, fabric and ceramics of China.
"The Chinese, when they wish for rain, make a huge dragon out of wood and paper and carry it in procession; but if it does not rain, then they destroy the dragon. Chuang-tzu maintains that this arises from the fact that the dragon and the serpent, invested with the most profound and all-embracing cosmic significance, are symbols for 'rhythmic life'." 
The Chinese calendar runs in cycles of twelve years, each named after a different creature:
Rat, Ox, Tiger, Hare, Dragon, Snake, Horse, Sheep, Monkey, Rooster, Dog and Boar.
But why is the dragon included here, alongside eleven very real species that are alive today? It might just be a zodiacal image that snugly fits a pattern of stars, but if that were so, if the patterns were so obvious, then why doesn't the western zodiac contain the same symbolism?
Five clawed dragons, especially yellow ones, were the most fearsome and powerful of their kind. It was once the law in China that only the Emperor could use the symbol of a five-clawed dragon. If someone other than the Emperor was caught wearing this symbol, he or she would be put to death.
In Chinese legends dragons are capable of many things. They tend to appear at favourable moments to indicate periods of prosperity. But if disturbed they might cause a drought by shifting all the water of the area into baskets, or they could choose to eclipse the sun. They were benevolent yet also moody and volatile. Historically the worst floodings in China have been attributed to a mortal upsetting a dragon.
In the beginning, according to Chinese mythology, there was only a cosmic egg. Within it, amongst the swirling darkness of chaos, slept a giant called P'an Ku, who had been developing for eighteen thousand years. Upon awakening he smashed the egg and allowed the darkness to pour out, as well as light that had been trapped within the chaos.
The darkness fell and created earth, while fragments of light rose up and created heaven. Disturbed by the idea that chaos could return if the light and dark were to mix, P'an Ku set himself the task of keeping the earth and sky apart until he could be sure all was safe.
After tens of millennia P'an Ku decided that everything was okay - so he sank into the earth and died. His final breath became the wind and clouds. His body and limbs formed the mountains and hills, and his blood flowed as streams and rivers. Vegetation grew from his hair, and his teeth gave us precious jewels. P'an Ku created order out of chaos. 
A beautiful creature emerged from the heavens and saw the remains of P'an Ku. She was the dragon goddess Nü-Kua, one half woman and one half dragon. All alone on a beautiful planet she decided to create humans by fashioning them out of clay, and animating them with her breath of pure love. 
 Ovid's Metamorphoses.
 Man-Ho Kwok, The Feng Shui Kit: The Chinese Way to Health, Wealth and Happiness, at Home and at Work, (Boston: Charles E.Tuttle Co. Inc., 1995) page 7
 Anastasia Saraonov, Anastasia's Eclectic Alcove, "P'an Ku & Nü-Kua", (28 May 2000)