The ninth celestial element in Hindu mythology, frequently termed the ‘shadow planet’. Ketu is associated with sorrow and material loss that foster spiritual development. The tenth element, Rāhu, is the head of the snake that swallows the sun or moon, causing eclipses, while Ketu forms the tail. Ketu is associated with spirituality, material prosperity, good health, antidotes to snake venom and poisons. He may be represented as a half-human, half-snake figure, with a trident and a bird.