Alduin

Alduin is an evil dragon and the main villain of The Elder Scrolls V: Skyrim. He is the son of the main god in the series, Akatosh, and his evil counterpart who intends to use an army of dragons to destroy the world.

Long ago, Alduin was defeated by using an Elder Scroll to banish him to a random point in time from where it was hoped that he would never return. Unfortunately, it actually sent him to the time the game takes place.