"It" is a horror short story by American writer Theodore Sturgeon, first published in Unknown of August 1940 (volume 3, number 6). The story deals with a muck-monster that emerges from a swamp, and terrorizes a family who lives nearby. The creature has no emotions, and is simply curious about the things that it observes. Its terrifying strength allows it to grab animals and people and tear them apart, to see how they work. Ultimately, the creature is revealed to have formed around a human skeleton.
P. Schuyler Miller described "It" as "probably the most unforgettable story ever published in Unknown".[1] The story was published in book form in Sturgeon's first short story collection, Without Sorcery (1948).
The story inspired many similar characters in comic books, including Swamp Thing and Man-Thing.[2]