Physical Characteristics: The Sandworm was the predominant lifeform on Arrakis, both honored and feared; vital and deadly. The sandworms were extremely territorial; as soon as two worms sensed each other's presence, they let out chuffing roars of challenge, bellowing melange-smelling exhaust from their cavernous throats. SizeEdit

By anyone's standards, Sandworms could grow to an enormous size. Dr. Yueh cited that specimens "up to 450 meters long" were spotted by observers in the deep desert. To make a comparison, the largest animal on earth was believed to be a Blue whale measuring in at only 33 meters, or about 12% of an average sandworm's length.

Many things commonly associated with Arrakis are surrounded in myth and mystery, and the sandworms are no exception. Some people believe that worms from 700 to even 1000 meters existed in the southern pole regions. This was neither confirmed nor denied. See Paul Atreides during his trial of the sandrider for further reading regarding their maximum observed size.

However there is some contention regarding these estimates as Harvester Factories were said to be 120 meters long and still the diameter of a sandworm's maw (or at least the sand displaced by its maw) was described as twice that width. Although this particular specimen was stated to be a large example of the species, a Sandworm with jaws 240 meters in diameter would exceed in size even those of myth which could supposedly be sighted in much deeper desert than the typical spice mining region.

• Centipede
• Trapdoor Spider
• Biting Wasp
• Wormfly
• Desert Bat
• Kit Fox
• Kangaroo Mouse
• Desert Hare
• Desert Hawk
• Dwarf Owl
• Eagle
• Desert Owl
• Scorpion