Ragnarök

Someday, when the Norns decree it, there shall come a great winter unlike any other the world has yet seen. The biting winds will blow snow from all directions, and the warmth of the sun will fail, plunging the earth into unprecedented cold and darkness. This winter shall last for the length of three normal winters, with no summers in between. Mankind will become so desperate for food and other necessities of life that all laws and morals will fall away, leaving only the bare struggle for survival. It will be an age of swords and axes; brother will slay brother, father will slay son, and son will slay father.
The wolves Sköll and Hati Hróðvitnisson who have chased the sun and the moon since the beginning of time will finally catch their prey, as Sköll swallows the sun and Hati swallows the moon, darkness will be left as the stars disappear, leaving a dark void in the heavens. The great tree Yggdrasill that holds all 9 worlds will tremble, and all the trees and mountains will fall down. Miðgarðsormr, the Midgard serpent, also known as Jǫrmungandr, who wraps around all of Midgard holding the worlds oceans in, will finally break loose and make landfall onto the lands, and the oceans will flood all of the lands. Surtr the fire jötunn will come from the south bringing giant fires and a giant bright sword, and he will do battle with the Vanir god Freyr who is also of the Æsir, and will defeat Freyr, leaving his fires to engulf the entirety of the Earth. The mighty giant wolf Fenrir will break free from his thin chain Gleipnir, and will run free across the Earth, with fire blazing from his eyes and nostrils, will run across the earth, with his lower jaw on the ground and his upper jaw against the top of the sky, devouring everything in his path. Jǫrmungandr will spit his venom over all the world, poisoning land, water, and air alike. Loki the trickster god will break free from the chains that bound him to a rock.
These convulsions will shake the ship Naglfar. This ship, which is made from the fingernails and toenails of dead men and women, will sail easily over the flooded earth. Its crew will be an army of Jötunn, its own captain being Loki. The dome of the sky will be split and from the crack emerge the fire-giants from Múspellsheimr. Their leader is Surtr. As they march, the rainbow bridge to Ásgarðr, the home of the gods across Bitfrost, the bridge will break and fall behind them. An ominous horn blast will ring out; this will be Heimdall blowing the Gjallarhorn to announce the arrival of the moment the gods have feared. Oðinn will anxiously consult the head of Mimir, the wisest of all beings, for counsel. The gods will battle, knowing what is prophesied for them. They will arm themselves and meet their enemies on a battlefield called Vigriðr. Oðinn will fight the mighty Fenrir and by his side will be the einherjar, the host of his chosen human warriors whom he has kept in Valhalla. Oðinn and his men will be killed and swallowed. Viðarr, on one of his feet will be the shoe that has been crafted, it has been made from all the scraps of leather that human shoemakers have ever discarded, and with it Viðarr will hold open the monster’s mouth. Then he will stab his sword through the wolf’s throat, killing him. Garmr and Týr will slay each other. Heimdall and Loki will do the same. Freyr and Surtr will kill each other. Þor (Thor) and the giant seroent Jǫrmungandr will fight each other Þor will slay the serpent, but covered in so much of its venom he will die. He will take nine paces before falling dead himself and adding his blood to the already-saturated soil of Vígríðr , also called Óskópnir. Then the remains of the world will sink into the sea, and there will be nothing left but a void.
Creation and all that has occurred since will be completely undone, as if it had never happened. Some say that that is the end of the tale – and of all tales, for that matter. But others hold that a new world, green and beautiful, will arise out of the waters. Viðarr and a few other gods, Váli, Baldr, Höðr and Þor's sons Móði and Magni will survive the downfall of the old world, and will live joyously in the new one. A man and a woman, Líf and Lífþrasir will have hidden themselves from the cataclysm in a place called Hoddmímis holt and will now come out and populate the lush land in which they will find themselves. A new sun, the daughter of the previous, will rise in the sky. All of this will be presided over by a new, almighty ruler.

The first one with no rebirth is the older pagan version.
The second one is the one made with Christian influence.