An evil twin is the concept in fiction (especially science fiction and fantasy) of someone equal to a character in all respects, except for a radically inverted morality (and often some changes in appearance, for the audience's convenience).

This can be sophisticated or simple. Most often, it is the latter, with the evil twin being a stereotypical villain. A closely related concept is that of an entire mirror universe, containing only evil twins of the characters in the regular universe (and "good twins" of evil people).

The exotic plot devices inherent in science fiction or fantasy allow the introduction of evil twins much more readily. Such ideas as cloning and time travel offer more opportunities for the twin to arise and their tendency to become exact polar opposites is magnified, rather the just slightly different characters.

Evil twins allow writers to compare the beliefs and opinions of their characters not with other characters but effectively with the same character. The basis of a characters beliefs and morality can then be explored through the distorted mirror image of their twin. In film and television the evil twin usually offers an actor the chance to play the same part but with an entirely different approach.

Origins

The similarities and differences of twins has long held a fascination for writers. Perhaps the oldest depiction of this idea is the biblical story of Cain and Abel in which one brother is the jealous counterpart of the other. Dualism and the conflict between good and evil is an important element in religion and mythology.

The concept also has its roots in the notion of a doppelgänger, a ghostly double whose appearance is an ill omen. The evil twin expands on this by being concrete and interacting physically with the world.

Appearances

Evil twins have found their niche in a large number of comic books and television shows. The Stephen King novel The Dark Half is about an evil twin, of sorts.

The short stories William Wilson by Edgar Allan Poe and Shatterday by Harlan Ellison are doppelgänger stories.

Equally, Robert Louis Stevenson's Jekyll and Hyde is very much an evil twin story despite the twins being just different aspects of the same person.

In the Star Trek universe there is an entire mirror universe, in which the people and political entities of the Star Trek shows are duplicated with reversed moralities and slight cosmetic differences. The "evil Spock" from the Star Trek mirror universe had a goatee while the real Spock and nearly all other Vulcans were clean-shaven; as a result, many evil twins in satirical works have goatees.

Also in the Star Trek universe, the android Data had an evil twin named Lore, who was emotional and deceptive in counterpart to Data's own logic and morality.

In the Knight Rider television show, David Hasselhoff's character, Michael Knight, had an evil twin named Garth Night. His car KITT had an evil twin called KARR.

The concept has been lampooned in a Halloween episode of The Simpsons, with a doctor stating that one of the twins is always evil. In this episode, it was revealed that Bart was the evil twin.

In Futurama , the robot Bender has a twin, Flexo (with a metal goatee). It was later revealed that Bender himself was the evil one of the two. In another episode, the show spoofs the concept of evil twins when the Professor creates a box with mirror universe in it. When the crew goes into it, they have an argument with the twins over which universe is the "evil" one.

In South Park, Eric Cartman's Evil Twin from another dimension has a goatee, but since Cartman is already abraisive and mean, the "twin" is much preferred by the inhabitants of this universe.

In Sunset Beach , Ben has an evil twin, who becomes involved in a plotline where Ben is accused of murder.

In the Mario series, Wario and Waluigi are evil versions of the Mario Bros

See also

• Bizarro