Cat's Eye gemstone is governed by the planet Ketu. As per Shri Bhagwat Puran, Rahu and Ketu were actually one in the same body; one person. While churning a nectar pitcher called Kshir Sagar that was going to produce nectar, demigods and demons clashed for drinking the nectar. To pacify the situation, Lord Vishnu took the form of an attractive woman called Mohini and began to distribute the nectar. A demon named Rahu found out that the Lord isn't distributing honestly. Therefore, Raha secretly joined the divine gods taking a form of a god. Moon and Sun noticed this and told Lord Vishnu about this. The Lord slashed the head of Rahu who had just started to drink the nectar that remained in his throat making him immortal. But the body was separated in the opposite direction that became demon Ketu.
