The snake or dragon that causes eclipses by swallowing the moon or the sun in Hindu mythology. One of the nine celestial elements in Vedic astrology,  Rāhu is associated with deception, manipulation, cheating, lying and poisons. He is also strongly connected with material ambition and success. He works with the ‘shadow planet’, Ketu, to swallow the sun or moon. He is the head of the snake while Ketu forms the tail.