Resemblance Reveal

The character long established as The Unseen or hitherto always masked is finally revealed and turns out to look like (but not to actually be) someone famous or otherwise important in the story, with various implications (from blood relation to supernatural connections).

Subtrope of The Reveal. Compare/contrast Stranger Behind the Mask.

Examples of Resemblance Reveal include:

Anime and Manga

• In Scrapped Princess, "Lord" Celia Mauser looks exactly like Pacifica Casull, only her hair is lighter blonde.
• This done with Hohenheim and Father in Fullmetal Alchemist. There's initially some Plot Based Photograph Obfuscation of a photo of Hohenheim, and even when Father himself is sort of obscured, there's enough shown of him to suggest he and Hohenheim are the same person. Even though the two turn out to be separate people, they do look pretty much identical.
• One Piece has a character named Duval who is introduced masked, and it turns out that he looks almost exactly like one of the protagonist's Facial Composite Failure Wanted Poster, which lead to a lot of grief for him and is why he started out as an antagonist.
• Fairy Tail: The Fairy Tail mage Mistgun not only concealed his face, but also made a habit of casting blanket sleep spells on any room he walked into. He was that paranoid about being recognized because he is eventually revealed to look just like Erza's childhood friend Jellal. Justified since Mystogan is actually the alternate universe/Edolas version of Jellal.
• Nove of Magical Girl Lyrical Nanoha Striker S, whose face was hidden in shadows when she was first introduced, is revealed to look just like Subaru, except with different hair and eye colors, due to her being the third clone of Quint Nakajima.

Literature

• In Perelandra, the King of Venus is revealed to Look Like Jesus.
• Arthur C. Clarke did this in Childhoods End, where Karellen reveals himself to look exactly like the Devil.

Live Action TV

• The Cliff Hanger of Season 4 of Star Trek: The Next Generation was that the unseen Romulan Commander was Tasha Yar's daughter, played by the same actress.
• The Reveal of Java and Siva, Ebony's sisters in Series 4 of The Tribe. The sisters unmistakeably look like Ebony, with a similar figure, facial features, poise and long, thin braids. Prior to the reveal, they spent several episodes wearing robot-like masks.
• A borderline example in The X Files episode "Jose Chung's 'From Outer Space'", there is an Man In Black who keeps to the shadows throughout the episode, but is eventually revealed to look like Alex Trebek (because he was played by him). Trebek is not particularly important in-story, but the fact that a Man In Black looks like a popular TV host further discredits Mulder's account of the encounter.

Video Games

• All to common in Kingdom Hearts. In the second game, Xemnas removes his hood revealing his face to be very close to the villain of the first game (fittingly, because they are two halves of one evil person) and in Birth by Sleep Vanitas's facial mask melts away revealing his face to be identical to The Hero Sora's but with black hair and Eyes of Gold.
• At the end of the first Blaz Blue it's revealed that Noel and Nu-12 both look alike...because Noel's a Prime Field Device. Then, in the sequal it's reveal that all the PFD look the same because they're clones of Ragna and Jin's sister. Makoto's story mode has an in-universe version when she looks at the "failed" devices near the cauldron (which shunted her into an alternative universe where Noel was never "born") and finds that they all look like Noel (her best friend).

Webcomics

• Tarquin from The Order of the Stick, who looks like Elan, because he is his father.