Worm is a self-published web serial by John C. "Wildbow" McCrae and the first installment of the Parahumans series, known for subverting and playing with common tropes and themes of superhero fiction. McCrae's first novel, Worm features a bullied teenage girl, Taylor Hebert, who develops the superpower to control worms, insects, arachnids, and other simple lifeforms. Using a combination of ingenuity, idealism, and brutality, she struggles to do the right thing in a dark world filled with moral ambiguity. It is one of the most popular web serials on the internet, with a readership in the hundreds of thousands. A sequel, titled Ward, was published from November 2017 to May 2020.

In literature, a serial is a printing or publishing format by which a single larger work, often a work of narrative fiction, is published in smaller, sequential instalments. The instalments are also known as numbers, parts, fascicules or fascicles, and may be released either as separate publications or within sequential issues of a periodical publication, such as a magazine or newspaper.