Nibiru. The ancient Sumerian texts depicted a large planet (Nibiru, today we call it Planet X) that entered the solar system very specifically in one of their drawings, and told how it would leave fairly quickly after it had come. In passing, it can have drastic effects on the Earth and other planets in the solar system. Annunaki. These ancient Sumerian texts also depict a race called the Annunaki (Anunaki), a race of beings that live on Nibiru, Planet X.
According to the Anunnaki themselves, our solar system has one more member, a huge planet that is orbiting the sun in a 3,600 years long ellipse. They called their planet Nibiru, which means "the planet