Once upon a time, on a blue planet, lived two twin dragons, El Niño and his sister La Niña. One could never be woken up while the other was. They regulated the climate of the great ocean, the first making the lands of the East wetter and the lands of the West dryer, the second doing the opposite. Their moods were so terrible that they threatened a large part of the planet disturbing its climate balances, spreading fires and floods throughout entire kingdoms. They spent years sleeping in their lair, only to awake again, never letting the people entirely forget them.
Awaking El Niño
And so it had been for years after years through the ages of (Middle) Earth. The small folk and the royals had learnt to live with the beasts moods, so much that they did not particularly pay attention as a group of brave Dwarf explorers dug into the depths of the planet to find a precious treasure. They called it black gold. It contained raw power, and magically helped the humans to rise above their conditions. It made them rich and the richer they got, the greedier they became.