Fictional depictions of worms

Worms have played major roles in world mythology and its associated literatures. The word was often used to describe creatures now classified as caterpillars, millipedes, snakes, maggots, and lizards, along with dragons. Its symbolic meaning is divided between death and renewal.

Worms continue to play mixed roles in modern cultures. The current usage of worm as a type of malicious Internet software is derived from a 1975 science fiction novel, Shockwave Rider. More positive interpretations, based on the concept of the friendly 'bookworm' or mutated forms of the common earthworm, are found in many recent books, especially those written for children.

On Pink Floyd's album The Wall, worms were used as "symbols of negative forces within ourselves."

Although more usually used to describe the common earthworm, the English language word "worm" derives from Old Norse orm and Anglo-Saxon wyrm, meaning "serpent" or "dragon". The synonymous usage of worm and dragon in English lessened during the following centuries. Samuel Johnson's dictionary drew a distinction between worms and dragons (while retaining the word serpent as a definition of worm) and the last synonymous usage of worm and dragon as noted in the Oxford English Dictionary dates to the 17th century.

Nidhogg (the 'Dread Biter') and Midgard's Worm were two of the most famous "Worms" in Viking mythology. At the 'still point of the turning world' the Vikings believed the ash tree Yggdrasil bore the weight of the universe. One of its three roots stretched over the underworld Niflheim where the dragon Nidhogg gnawed at it in an attempt to destroy creation – hence its name 'The Dread Biter'. This legend was later used by fantasy writer Terry Pratchett.

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