The origin of the sandworm in the West is said to be the Old English "Wyrm," which meant a dragon or giant serpent. In Norse mythology and *Beowulf*, the wyrm was an evil dragon hoarding golden treasure underground, but in *Dune*, the forefather of modern sci-fi, it was adapted into a giant creature guarding precious "spice" in the desert. Its image also mixed with urban legends of the "Mongolian Death Worm," an unverified creature (UMA) rumored to inhabit the Gobi Desert, forming a robust monster archetype. On the other hand, in Japan, where there is no vast desert environment (limited to places like the Tottori Sand Dunes), this monster was imported as a symbol of awe toward the "harsh, dry wilderness of an unknown foreign land." While many classical Japanese yokai are born from "water" or "moisture" (Kappa, Kawa-akago, Akaname, etc.), the Sandworm is a monster born of absolute "dryness," positioning it at the polar opposite of Japanese yokai. Despite being a monster with no traditional folklore, the countermeasure "if the sand beneath your feet vibrates, you must absolutely not run (because it will sense the vibration and eat you)" is widely shared among game enthusiasts in modern Japan as if it were an age-old legend. It is a highly fascinating case study in modern yokai studies, where a pseudo-folklore was formed from scratch through the power of media.