Their larvae produce a drug called melange (known colloquially as "the spice"), the most essential and valuable commodity in the universe because it makes safe and accurate interstellar travel possible.

The sandworms are reverently called Shai-Hulud by the planet's indigenous Fremen, who worship them as agents of God whose actions are a form of divine intervention.

"[8] 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.

They are reverently called Shai-Hulud by the planet's indigenous Fremen, who worship them as agents of God whose actions are a form of divine intervention.

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 ..."[5] Sandworms grow to hundreds of meters in length, with specimens observed over 400 metres (1,300 ft) long[13][14] and 40 metres (130 ft) in diameter, although Paul becomes a sandrider by summoning a worm that "appeared to be" around half a league (1.5 miles (2.4 km)) or more in length.

[18] Their leathery remains previously having "been ascribed to a fictional 'sandtrout' in Fremen folk stories", Imperial Planetologist Pardot Kynes had discovered the Little Makers during his ecological investigations of the planet, deducing their existence before he actually found one.

[19]The sandtrout are described as "flat and leathery" in Children of Dune, with Leto II noting that they are "roughly diamond-shaped" with "no head, no extremities, no eyes" and "coarse interlacings of extruded cilia".

[19] When water is flooded into the sandtrout's excretions, a pre-spice mass is formed; at this "stage of fungusoid wild growth", gases are produced which result in "a characteristic 'blow', exchanging the material from deep underground for the matter on the surface above it".

Rhythmic activity as minimal as normal walking on the desert surface of Arrakis attracts the territorial worms, which are capable of swallowing even the largest mining equipment whole.

A worm can be ridden for several hundred kilometers and for about half a day, at which point it will become exhausted and sit on the open desert until the hooks are released, whereupon it will burrow back down to rest.

[22] Paul also uses worms for troop transport into the city during the Battle of Arrakeen after using atomic weapons to blow a hole in the Shield Wall.

The one exception is a young girl named Sheeana, an Atreides descendant who possesses a unique ability to control the worms and safely move around them.

An unfixed knife requires proximity to a human body's electrical field to prevent its eventual disintegration, while fixed knives are treated for storage.

[5] This is no longer the case by the time of Children of Dune (1976), and numerous groups attempt to smuggle sandworms off Arrakis and transplant them to other planets so as to break the Atreides' monopoly on spice production.

This layer gives Leto tremendous strength, speed, and protection from mature sandworms, which mistake his sandtrout-covered body for a lethal mass of water.

Bene Gesserit Mother Superior Taraza becomes aware in Heretics of Dune (1984) that humanity is being limited by the prescient dream of Leto, and controlled by him through his worm remnants.

In the Prelude to Dune prequel trilogy by Brian Herbert and Kevin J. Anderson (1999–2004), the Tleilaxu initiate Project Amal, an early attempt to create synthetic melange to eliminate dependence upon Arrakis.

Sure to die should they be without the spice, a group of Navigators commissions Waff, an imperfectly awakened Tleilaxu ghola, to create "advanced" sandworms able to produce the melange they so desperately require.

Adapting to their new environment, these seaworms quickly flourish, eventually producing a highly concentrated form of spice, dubbed "ultraspice".

In the 1984 David Lynch film Dune, the sandworms were designed by special effects modeler Carlo Rambaldi for a budgeted $2 million.

[28][29] Roger Ebert called Lynch's sandworms "striking", but noted, "the movie's special effects don't stand up to scrutiny.

[31] Daniel D. Snyder of The Atlantic was impressed by the "gargantuan" appearance of the sandworms thanks to the "staggering sense of scale" achieved by the miniature sets created by Emilio Ruiz del Río.

"[32] Hoai-Tran Bui of /Film noted that "the popular image of the sandworm comes from David Lynch's 1984 film, which depicted the massive creatures as fleshy, phallic-looking monsters.

[38][39] Deborah D. McAdams of Broadcasting & Cable suggested that the images of "gigantic computer-generated sandworms munching down huge machines and people like popcorn" contributed to the 2000 miniseries' record-breaking ratings.

[40] Regarding his 2021 film Dune, director Denis Villeneuve said: I kept saying to Patrice Vermette, my production designer, "I want the worm to be like a prehistoric creature, something that has been living and evolving for 100,000 years."

Sandworms are a featured element in the 1992 real-time strategy video game Dune II: The Building of a Dynasty,[43] primarily as destroyers of the player's spice Harvesters, assault tanks, and other equipment.

[59] For the 2024 release of Denis Villeneuve's Dune: Part Two, AMC Theatres introduced a popcorn bucket with the likeness of the giant sandworm, featuring a lid with flexible plastic "teeth" that appear to consume the moviegoer's hand as they reach in.

[61] The sandworms have been called "iconic" to the franchise,[12][28][62] and "synonymous with the Dune series", having appeared in nearly every novel, on several book covers, and in all of the television, film, and video game adaptations.

[33] Hoai-Tran Bui of /Film noted that they are an "essential to the narrative of the story",[33] and Lindsey Romain of Nerdist deemed the creatures "extremely important to the plot and the very fiber of the Dune universe.

[67][68] In August 2023, University of Kansas paleontologist Rhiannon LaVine named a newly-discovered, 500-million-year-old marine polychaete worm Shaihuludia shurikeni after Herbert's fictional sandworms.