- In the Harry Potter fanfic Danse Macabre, Tom Riddle is this so far. He is mentioned several times, but has yet to appear.
- In The Parselmouth of Gryffindor, the villainous Mosag is behind the darkest event in the story but is defeated off-screen by Dumbledore before the heroes, or the readers, have had a chance to meet her.
- Rafiki in The Lion King Adventures. He is mentioned a few times in the series, but was never seen. He presented Simba at his birth, and also confirmed that he had the Kulaani illness in Sick Simba. Word of God claims he died after Series Three.
- Not only is Hayate never shown in Perfection is Overrated, but nothing is revealed about this person apart from being Toki's most important person, someone for whom she'd risk a temporal paradox- not even Hayate's gender is revealed. The Usurper wonders what Toki sees in Hayate, but she refuses to elaborate, a reference to the shallow and hastily established romances some Mary Sue characters have.
- Crime king Felix Drachner from What About Witch Queen? has never been seen by any POV, only heard once. He apparently "dropped off the surface of Earth" about ten years before and remained free despite being chased by three governments, many guilds and countless criminals. Despite not appearing, he's likely the biggest player in the fic, causing among others, Anna's kidnapping, Weselton attacking Arendelle and Elsa's assassination attempt.
- Enforced in The Universiad with regards to the Moderators. Due to Gideon (the author)'s insistence that only the appropriate users can "play" the characters representing themselves, and none of the actual mods deigning to join in, they will remain offscreen for the foreseeable future.
- The character Hope from Justice Society of Japan is a huge fan of Wild Tiger, but the character never appears on-screen (not counting a dream sequence).
- Bad Future Crusaders has Queen Twilight Sparkle. It was her FaceHeel Turn and transformation into a despotic tyrant that instigated the plot, but as of this writing, she's yet to appear personally.
- Weiss Reacts has Weiss' grandfather. He set in motion most of the tragedies that befall the characters in the backstory but isn't actually seen during the present as of this writing.
- The Bridge:
- The pony characters speak of Queen Chrysalis with dread frequently, and it's a plot point that Mothra Lea's Equestrian form slightly resembles her, forcing her to hide her appearance to prevent a panic. At one point, Destroyah nearly kills a Changeling and it escapes and decides to report to Chrysalis what happened. It takes until Chapter 31 for her to appear in person.
- Flash Sentry's father Stalwart Sentry is fondly spoken of by the others as one of the greatest members of the Royal Guard who ever lived and personally trained Shining Armor and Blueberry Frost. He is mentioned to be living in retirement. In chapter 38, he appears in a flashback.
- In the spin-off The Bridge: Sound of Thunder, Raiga's Mirror Universe counterpart is mentioned when Raiga is compared to her. Main universe Raiga is a Boisterous Bruiser while she is a Shrinking Violet.
- Fire Emblem Fates: Aftermath: Xander's fiancé/wife is mentioned multiple times, but she never shows up in person and her identity is unknown to the reader.
- Teenage Mutant Ninja Turtles - Vengeance of the Foot Clan: While mentioned frequently, the Turtles don't physically appear at all until the penultimate chapter of War of the Heart of Darkness; a big part of Ethan, Jess, and Kaela's mission is finding them.
- Pokémon Story: Sinnoh Journey: Two characters named Isabella and Caecus were namedropped when Ian talked to Jacob. They never make an appearance in this story.
- crawlersout: Since the beginning of the story is set during Tom's pre-Hogwarts years, Albus Dumbledore has yet to appear, despite being slated to be a major character. His influence is still felt, however, as Fem!Harry is still very fond of him and it colors her... complicated relationship with her Stalker with a Crush, his former best friend and own crush, Gellert Grindelwald. Grindelwald himself is similarly fond of Dumbledore in spite of himself, but holds somewhat of an enmity/rivalry with the man (despite having not interacted with him in over thirty years by that point).
- Ultra Fast Pony is an Abridged Series, so it's forced to keep important characters off-screen when it deviates too far from the original episodes' plots. So, in "Mob Wars", a Canon Foreigner named Snuggle Berry wins an award for being an upstanding, much-loved member of the community, then dies in a rabbit stampede, all without appearing on screen once. And Princess Luna, in spite of having a lot of screen time in the first two episodes, is shoved off-screen for the rest of season one. There are several references to Luna being the royal court's Butt-Monkey, and a several-episode-spanning subplot in which she gets kidnapped—all without her putting in a single appearance.
- Childhood's End has the Player Character hunter. The main group hasn't met him or her yet, but they're mentioned by the Chapel Dweller and is the one who killed Father Gascoigne.
- In Neither a Bird nor a Plane, it's Deku!, major DC Comics superheroes like Wonder Woman are regularly mentioned but never seen due to working outside of Japan. Other frequently mentioned characters include Batman, Aquaman, and Alan Scott.
- Power Rangers Clockwork has Aricin Velothi, the son of Asgaut and Brynja Velothi. So far, he only appears in a painting and is mentioned frequently in his father's journals during Chapter 2, but he hasn't made a full appearance.
- In the Triptych Continuum, the Strawman News Media tycoon Murdocks fits this role. Even Celestia doesn't know any more than his name, approximate age, and that 'he' is the right pronoun. All his reporters are legally (and, it's implied, illegally) enjoined from sharing anything about him, and asking prying questions thereof is possibly the only way to get a Murdocks reporter to back off.
The Ghost / Fan Works