The Fon of West Africa have a legend that says:
In the beginning, the world was created by Nana-Buluku, the one god, who was genderless. Nana-Buluku made itself a companion named Aido-Hwedo, who was a rainbow serpent. The dung from this serpent or dragon created the mountains, and nourished the earth so that plants could grow. The writhings of the dragon created rivers and valleys.
When the world was complete, it was so overladen with plants, animals and mountains that they feared the world might collapse. Aido-Hwedo offered to help by forming a great circular loop, with its tail in its mouth, and enfolding the world (see Ouroboros).
Because Aido-Hwedo could not tolerate heat, Nana-Buluku created a great cosmic ocean for him to live in, and there he has stayed. He was fed iron bars by red monkeys that lived beneath the sea. If and when the monkey's iron supply runs out, Aido-Hwedo will be so hungry that he will eat his own tail. Then,
"...his writhings will be so terrible that the whole earth will tilt, and then slip into the sea, and that will be that!" 
The ancient legends of the Nordic race were often practical warnings, in allegorical form, against the dangers of the world. The destructive power of nature was typically symbolised by predatory animals. The wolf was the more common symbol, but it was the dragon which represented peril on the grand scale. The dragon's favourite victim was the virgin: a fertile woman who represented the source of human life, and the continuation of our species. Just as she indicated how precious our existence was, and how easily it can be lost due to major catastrophes, the dragon represented those terrible scenarios himself.
Originally there were two worlds, one of fire and one of ice. When they became joined, the ice melted and from the water came Ymir, an enormous sleeping giant. From the sweat of his armpits a race of Frost Giants were created. The goddess Audumla had also formed from the melting ice, and she gave birth to a dynasty of gods. Three brothers - Odin, Vili, and Ve, were the first Aesir gods. They attacked the sleeping Ymir and killed him. His wounds let loose a torrent of blood which drowned all of the Frost Giants except for one family that managed to float to safety, thus saving their race from extinction. Odin and his brothers proceeded to chop up Ymir's body and from the pieces they made the levels of all the worlds. Ymir's flesh became land, his bones formed mountains, his hair grew as trees, and so on. Holding it all together was the Norse symbol for the universe - the giant ash (or yew) tree Yggdrasil. Its shaft was the pivot of the revolving heavens, and its limbs and roots spread into a variety of worlds or planes of existence. There were levels within levels, all connected and each containing beings such as gods, elves, humans, giants, dwarves and the dead.
One world was above ground, that of Midgard (Middle-Earth), the world of human beings. Below it Yggdrasil's immense roots descended into three levels: one into Asgard, the second into Jutanheim, and the third into Niflheim.
Asgard was the dwelling of the gods.
Jutanheim was an eternally-frozen land and abode of the Frost Giants; enemies of men and gods.
Niflheim, was a region of cold and darkness, the land of the dead. Imprisoned there was the fallen trickster-god Loki. Mating with a giantess he produced three monstrous beings - each of which were consequently forced into binding roles by the great Odin. Their first child was Fenrir, a huge wolf, who was imprisoned in Asgard. Hel was a woman, half alive and half corpse, banished to the kingdom of Helheim, where she fed and housed the dead. And thirdly Jormungand was a huge serpent which Odin threw into the sea, where it grew until it encircled the Earth while biting on its tail - an Ouroboros. His twisting and turning beneath the sea was the cause of storms and earthquakes. Nearby lay another giant serpent-dragon Nidhoggr, who devoured the bones of the dead as well as gnawing at the root of Yggdrasil, the axis of the world. [*]
ash tree Yggdrasil suffers anguish
More than men can know
The stag bites above; on the side it rots;
And the dragon gnaws from below".
Robert Graves, The White Goddess
As if the gnawing of a dragon wasn't enough, there were four deer and a goat living on Yggdrasil's limbs eating all the leaves and the trunk was infected with rot. All of these creatures were awaiting their release and the beginning of Ragnarok, the battle of the End of the World. The root that extended into Asgard was tended by the three Norns, Urdur, Verdandi and Skuld - goddesses representing the past, the present and the future. Each day they applied the healing water from Urd's Well to the trunk of Yggdrasil, chanting the Orlog - mysterious laws of the universe that the myths do not reveal to us - making sure that the great tree lived on, despite the attacks upon it. The giants were determined to eventually overthrow and destroy the gods, and Ragnarok occurred as prophesised. Battles raged for three years, followed by three summer-less years of terrible cold. Then a huge earthquake broke the bonds of Loki and his son Fenrir. The huge serpent Jormungand came ashore, making the ocean surge upon the land. The forces of good and evil met and did battle at the plain of Vigrid. Fenrir swallowed Odin. Thor killed the giant serpent Jormungand, but succumbed to its poison. The world was engulfed in fire and smoke and all those who fought were killed. The stars disappeared and the earth sank below the sea. Eventually a new, fertile world emerged, and it was populated by two humans who had hidden in the Yggdrasil tree. In another chapter we will discuss the relevance of a serpent gnawing on the axis of the world, and the disappearance of the stars. For the time being, it is enough to absorb how often dragons and "the end of the world" combine in global mythology.
She cloaked ferocious dragons
with fearsome rays
And made them bear mantles of radiance, made them godlike
(Enuma Elish, - Tablet III)
The "Enuma Elish" is the Babylonian creation epic, a thousand-line poem inscribed 4000 years ago upon seven clay tablets. It was probably a chant to help welcome in the Babylonian New Year. 
In this epic there is a huge dragon named Tiamat who is the personification of the ocean and chaos, who is the mother of all that exists, of even the gods. She is an uncontrollable creature made of "formless primordial matter" 
Her partner was Apsu, the personification of the freshwater abyss that lay beneath the Earth. With their union, when saltwater mixed with freshwater, the first gods were born - Lachmu and Lachamu, who begat Ansar and Kisar, parents of Anu, Bel and Ea.
These offspring irritated Tiamat and Apsu - so they decided to kill them all. Ea discovered their plans and struck first, killing Apsu in his sleep. When Tiamat heard of this she flew into a violent rage and created a legion of eleven monstrous creatures - a viper, a shark, a scorpion man, a storm demon, a great lion, a dragon, a mad dog and four nameless ones - which she assigned to her new husband, her son Kingu.
The young gods were terrified, knowing that they were no match for the powerful Tiamat. They persuaded Ea's son Marduk to be the champion of the gods by promising to make him the supreme god and ruler of the universe. Marduk fought well and was finally able to shoot an arrow into Tiamat's mouth, cleaving her dragon body in two. From her upper half he made the arc of the sky and from her lower limbs he created the earth. He also slaughtered Kingu, and from his blood and bones Marduk created the first humans. He then firmly fixed the stars, arranging the constellations of the zodiac, and created the moon - "sets him as a creature of night, to make known the days monthly without failing". 
Once again stars were integral to the story. Across nations and cultures the dragon is an emblem of destruction and anarchy, misdirected violence and untameable animal passions. The myth of Tiamat represented how destruction and chaos were transformed into order.
[*] NB: Early Sumerian and Akkadian artifacts
(circa 2500 BC) show pictures of a pole or tree which is called the "axis
mundi " - the world axis. It is the shaft that runs through and supports
the world. Guarding this tree or pole is a snake or pair of intertwined snakes.
 Robert T. Mason, The Serpent As Divinity, "The Devine Serpent in Myth and Legend," (28 May 2000)
 The Catholic Encyclopedia, Volume IV, Copyright © 1908 by Robert Appleton Company - Online Edition Copyright © 1999 by Kevin Knight http://www.newadvent.org/cathen/04405c.htm May 23 2000 --Nihil Obstat. Remy Lafort, Censor -- Imprimatur. +John M. Farley, Archbishop of New York