In literature, the concept of doppelgangers often explores themes of:

The term "doppelganger" is derived from which language?

In Edgar Allan Poe's short story "William Wilson," the protagonist encounters his doppelganger at a young age. What is the name of the doppelganger?

In Oscar Wilde's novel "The Picture of Dorian Gray," the protagonist's portrait serves as a kind of doppelganger. What happens to the portrait as Dorian's moral character deteriorates?

In Fyodor Dostoevsky's novel "The Double," the protagonist, Golyadkin, is haunted by his doppelganger. What is the name of the doppelganger?

In the film "The Prestige," directed by Christopher Nolan, two rival magicians, Robert Angier and Alfred Borden, use doppelgangers as part of their stage illusions. What is the name of Angier's doppelganger?

In the television series "The Twilight Zone," there is an episode titled "Mirror Image." What happens to the protagonist, Millicent Barnes, when she looks in the mirror?

In the anime series "Neon Genesis Evangelion," the protagonist, Shinji Ikari, encounters his doppelganger, Kaworu Nagisa. What is the name of the doppelganger's Evangelion unit?

In the video game "Silent Hill 2," the protagonist, James Sunderland, encounters a doppelganger of his deceased wife, Mary. What is the name of the doppelganger?

In the novel "The Sandman" by Neil Gaiman, there is a character named Dream who is the personification of dreams. What is the name of Dream's doppelganger?

In the film "Enemy," directed by Denis Villeneuve, the protagonist, Adam Bell, discovers that he has a doppelganger named Anthony Claire. What is Adam's profession?

In the television series "The X-Files," there is an episode titled "Doppelganger." What happens to the protagonist, Fox Mulder, when he encounters his doppelganger?

In the novel "The Dark Half" by Stephen King, the protagonist, Thad Beaumont, is a writer who is haunted by his doppelganger, George Stark. What is the name of Stark's novel?

In the film "The Double Life of Veronique," directed by Krzysztof Kieslowski, there are two women, Veronique and Weronika, who are doppelgangers. Where do they live?

In the novel "The Stepford Wives" by Ira Levin, the protagonist, Joanna Eberhart, moves to a town where all the women are beautiful and perfect. What is the name of the town?