Ever hear of the Sumerians?

They believe in a planet that orbits two solar-systems called Nibiru which is home to two races; the Anu and the Nephillium.
Every 3600 years this celestial body enters our solar system. According to Sumerian mythology the Anu came to earth and created a slave race, humans, by bonding their genetic material with that of homoerectus. The Anu were described as god-like, resembling humans only about twice as large. They used this slave race to mine gold and restore Nibirus atmousphere. After they were through they handed control of Earth over to the humans, but flooded it in attempt to wipe them out.

Nibiru was supposed to return in spring of 2003.