SHAI-HULUD: Sandworm of Arrakis, the 'Old Man of the Desert','Old Father Eternity,' and 'Grandfather of the Desert.' Significantly, this name, when referred to in certain tone or written with capital letters, designates the earth deity of Fremen hearth superstitions. Sandworms grow to enormous size (specimens longer than 400 meters have been seen in the deep desert) and live to great age unless slain by one of their fellows or drowned in water, which is poisonous to them. Most of the sand on Arrakis is credited to sandworm actions.