Apep

Apep (or Apophis or Apopis), a dragon of Chaos was an Egyptian dragon and can be seen as the opposite of the sun god Re (or Ra). Every day Apep fought with Re, in order to turn the world into darkness. Apep wanted to prevent Re in travelling from east to west across the sky each day. He fought with, storms and darkness and rain against Re. At the end of the day, Apep succeeded and Re made went into the Underworld. This is the moment when darkness (night) covered the earth instead of daylight. Re, however, was reborn the next day, as a matter of fact, he was reborn every day, so Apep had to fight the same battle with Re over and over. This battle can be seen as symbol of the cycle of life and death (information provided by Dragonfly).