A villain is a bad person, especially in fiction. Villains are the fictional characters, or perhaps fictionalized characters, in drama and melodrama who work to thwart the plans of the hero. As such, villains are an almost inevitable plot device, and more than the heroes, the villains are the crucial elements upon which plots turn. The etymology of word is from Old French villein, in turn from Late Latin villanus; it literally means a serf or a peasant, someone who dwells in a villa, which is to say, worked on a plantation.
Usually the word villain suggests that the villain's scheme stem from their own moral indifference or perversity of character. Supervillains are found in the melodramatic environs of superhero comic books, where an evil person with super powers is needed to be a realistic foil for the mighty heroes. These supervillains usually have recurring roles; some villains in more down to earth literature have become so popular that they have been reused in later works as well.
There are many villain stereotypes. A caricature of a common cliched villain can be seen at the right of this page. In the era before sound in motion pictures villains had to appear very "visually" sinister, and thus many villain stereotypes were born. The Rocky and Bullwinkle character, Snidely Whiplash, enemy of Dudley Doright, is a well known parody of this kind of character.
These stereotypes include black clothing (often quite formal, capes, top hats, etc), facial hair, sharp features, and a perpetually "angry" facial expression. Other non-visual villainous stereotypes include a habit of "evil laughter," a snooty or smarmy voice, and a haughty overconfidence that leads to the unnecessary explanation of one's sinister plans. This exposition, of course, is a fairly transparent plot device.
Are villains inherently more interesting than the heroes who oppose them? They are at least as indispensable to the stories they appear in, probably more so. Those who stand on the side of righteousness and goodness seldom have much choice but to respond, and little choice in how; for villains, all paths are wide open. Many believe that Satan, for Christians perhaps the ultimate villain, is the most interesting character in John Milton's Paradise Lost, for all that he is the embodiment of evil. Perhaps in the nefarious acts of many villains there is more than a hint of wish-fulfilment fantasy, which makes some people identify with them as characters more strongly than they do the heroes. Still, the writer's task in creating a villain is not an easy or a trivial one; a convincing villain must be given a characterization that makes his motive for doing wrong somewhat more convincing that Mephisto's gleeful but seemingly pointless mischief.
Some well known villains are:
Historical figures who often figure as villains in fiction