which they mistake for prey (smaller sandworms). To escape the notice of the sandworms, a traveller in the desert must learn to "walk without rhythm" in a manner that simulates the natural sounds of the desert. This element comes from Frank Herbert's experiences as a hunter and fisherman. He knew how to mask his presence from prey by techniques such as approaching from downwind and treading lightly. Frank Herbert's son Brian explained that "In Children of Dune, Leto II allowed sandtrout to attach themselves to his body, and this was based in part upon my father’s own experiences as a boy growing up in Washington state, when he rolled up his trousers and waded into a stream or lake, permitting leeches to attach themselves to his legs." John Schoenherr provided the earliest artwork for the Dune series, including the illustrations in the initial pulp magazine serial and the cover of the first hardcover edition. Frank Herbert was very pleased with Schoenherr's art, and remarked that he was "the only man who has ever visited Dune". Schoenherr gave the sandworm three triangular lobes that form the lips of its mouth. This design was referenced for the sandworm puppets that appeared in the 1984 movie adaptation of Dune. Description Sandworms are giant creatures found only on the desert planet Arrakis. They are worshipped as agents of God by the Fremen, who consider their actions a form of divine intervention. The Fremen also refer to the sandworms as "Makers" or "Shai-Hulud". Physiology Herbert describes sandworms as colossal terrestrial annelids with features of the lamprey. They have an array of crystalline teeth which are used primarily for rasping rocks and sand. During his first close encounter with a sandworm in Dune, Paul notes, "Its mouth was some eighty meters in diameter... crystal teeth with the curved shape of crysknives glinting around the rim... the bellows breath of cinnamon, subtle aldehydes... acids..." Sandworms grow to hundreds of meters in length, with specimens observed over long and in diameter, although Paul becomes a sandrider by summoning a worm that "appeared to be" around half a league () or more in length. These gigantic worms burrow deep in the ground and travel swiftly; "most of the sand on Arrakis is credited to sandworm action". Sandworms are described as "incredibly tough" by Liet-Kynes, who further notes that "high-voltage electrical shock applied separately to each ring segment" is the