Mirror Monster

He's the hot new mirror monster. Run'n his mouth about how the old guard is out of touch. "Bloody Mary" dates back to the 1500s. I am mirror monster. That's me!

—Bloody Mary, Gary and His Demons

Mirrors are inherently creepy objects. If you're looking in a mirror, there's also someone looking at you. A movement in a mirror can make you jump. It's no surprise that they're associated with badness.

But what if there were something more than just one's own reflection in the mirror? What if the mirror showed something else looking back at you?

This is the Mirror Monster! Though a mirror is really just a pane of glass and silver, in fiction it can become a gateway - something terrible could come out... or something terrible could try and suck you in. A Mirror Monster could be an image only visible in a mirror. It could be a ghost fettered to the world of the living by a mirror. It could be something which comes out of a mirror or communicates via mirror. The key thing about this trope is the horror is directly connected to the mirror itself.

Sometimes mirror monsters can be defeated by smashing the glass. Unfortunately, sometimes smashing the glass can free the mirror monster and allow it free rein (or make even more of them).

Compare with Mirror Scare, Mirror Routine.

Examples of Mirror Monster include:

Anime and Manga

JoJo's Bizarre Adventure has a couple of mirror monsters. The first one attacks your reflection in the mirror (or any shiny surface), which in turn damages you. The second actually pulls you through the mirror into the "mirror world".
In Kazuo Umezu's Scary Book: Reflections, the vanity of a girl who admires her beauty incessantly in a mirror causes her evil reflection to escape and attempt to take her place, driving her to the edge of insanity in the process.
- This story was parodied in the Ranma ½ manga, where the mirror is haunted by the girl's lingering presence, and now whoever looks into it will have their reflection pop out. They aren't so much evil as just incredibly annoying.
In one Slayers Non-Serial Movie,^{[please verify]} Lina and Naga ran afoul of a mirror that created clones of them. This mirror, showing the exact metaphysical opposite of the person who looks into it, creates a wimpy, demure Naga and a pathetic, weepy Lina.
Sailor Moon used this trope all throughout the Dead Moon arc of SuperS/early Stars, where Queen Nehelenia would trap people in mirrors in a "nightmare", a mirror leads to a portal to her evil dreamland, and in one episode she creates a house of mirrors and controls the Senshi's reflections and makes them psychoanalyze and hypnotize them, to convince them to give up.

Comic Books

This is the modus operandi of Flash rogue Mirror Master.

Film

Legend: Darkness first appears to Lily by stepping out of a mirror.
Prince of Darkness: Satan's father (the "Anti-God") is on the other side of a mirror trying to get through into our world.
Phantasm: At the end of the movie, the Tall Man emerges from a mirror to grab Mike.
Inverted with Ozma in Return to Oz. She's the girl queen of Oz and was imprisoned in mirrors as a reflection by Mombi.
The movie Mirrors had what turned out to be a demonic being inhabiting mirrors and attacking anyone who looked into them.
In the movie The Watcher in The Woods, Jan sees a blindfolded girl in a mirror. She turns out to be not a ghost, but trapped in another dimension.
There's a movie called In Dreams in which, at the very end, a mirror actually distorts and drags someone in.
In Night of the Demons there's a demon head that appears in a mirror, looking vaguely like a monstrous cow skull.
The Boogeyman in... The Boogeyman.
The mirror itself in Amityville: A New Generation.

Literature

In Robert Heinlein's The Unpleasant Profession of Jonathan Hoag, the Sons of the Bird are powerful evil entities that enter and exit our world through mirrors.
In the novel The Shadow of the Wind, Julian, as a lonely child, made up stories that he told to other kids that he had a sister who came to visit him through the mirror and lived with the devil.
In the fourth installment of Odd Thomas by Dean Koontz, something briefly materializes out of a mirror to collect someone's soul.
In the Discworld novel Witches Abroad, the villain uses mirror magic, and when she loses control at the end, her reflection reaches out of a mirror and pulls her in.
The Dresden Files: This is the reason Harry refuses to keep mirrors around his house. A lot of nasty critters can use them as doorways between the Nevernever and the real world, like the fetches in Proven Guilty.
The Stephen King short story "The Reaper's Image"
The Goosebumps book Lets Get Invisible features a mirror that turns you invisible, but if you stay invisible too long, your reflection forces you to switch places with it.
In Jonathan Strange & Mr Norrell, mirrors can be used by fey and magicians as gateways to the fairy realm. They're featured prominently near the end of the book.
Labyrinths of Echo had the Secret Investigations dealing with one of such creatures, and devouring the life-force, at that.

Live-Action TV

The Supernatural episode "Bloody Mary" had this, as it was about a variant of the Bloody Mary Urban Legend mentioned under Real Life. However, this Bloody Mary didn't always kill the person who summoned her: She instead kills someone with a secret that she feels makes them responsible for a death.
Part of the premise of Kamen Rider Ryuki, where Mirror Monsters are simply animalistic creatures that hunt humans and eat them. Some are contracted by the Riders to fight other Riders and Mirror Monsters. While some of the monsters are heroic, they still need to be fed, or they'll eat their contractor. Though they'll wind up eating them if the contract breaks.
- Ryuki's American adaptation, Kamen Rider Dragon Knight, is near identical except the heroes are never at risk of being eaten by the monsters they're contracted to. There's still scores of evil mirror monsters to deal with though. That and they're don't eat people but rather capture them.
Doctor Who, "Family of Blood": "If ever you look at your reflection and see something move behind you just for a second, that's her."
According to Grover on Sesame Street, seeing a monster in the mirror is not a cause for freaking out but an occasion to sing "Wubba wubba wubba wubba woo woo woo." After all, "That monster in the mirror, he just might be you."
The entire premise of Dark Oracle is that the kids' Evil Twins can reach them by coming out through the mirrors. To say this leaves everyone incredibly paranoid would be an understatement.
A program called Strange Paradise, conceived as competition for the original Dark Shadows, included at least one scene of a woman cringing away from a mirror which, rather than her reflection, showed a man in Renaissance clothing reaching menacingly toward her. Then he faded out of the mirror ... and there was a cut to a room where he'd apparently used TV cameras to produce the effect....

Newspaper Comics

There was a cartoon by Charles Addams (famous for inventing the Addams Family) in which a man in a barber chair with mirrors on either side has a virtually infinite series of reflections, one of them about three-fourths of the way down the line being of a monster sitting where he is sitting.

Professional Wrestling

During the WCW version of the Hulk Hogan/Warrior feud, one infamous segment involved Warrior appearing in the mirror of Hogan's dressing room. The idea was for the Warrior to only be visible to Hogan, as Eric Bischoff doesn't notice. The only problem with this: the Warrior was clearly visible to the commentators and people watching on TV.

Theatre

Walking with Shadows features a ghost in a mirror who tries to tempt a teenage girl to suicide.

Tabletop Games

Call of Cthulhu (tabletop game) supplement The Dreamlands, adventure "Lemon Sails": The Temple of the Oracle on Sarrub has a mirror which has been taken over by a wendigo-demon that attacks anyone who tries to use it.
Dungeons & Dragons has 'fetch' -- a monster from Abyss who pops through mirrors and kill people.
- In Forgotten Realms, Turmish even got the law that prohibits large mirrors for this reason.
Exalted gives us Szoreny, possibly the Mirror Monster. One of the Yozis, he used to represent The World Tree until he got turned inside out and became a grove of reflective trees laced with quicksilver. While his Charms haven't be statted up yet, it's theorized a lot of them would center around mirrors, reflection, and unseen connections.
The New World of Darkness has two variations of this. The Urban Legends sourcebook gives various rules about the homicidal ghost Bloody Mary, mentioned in the real life section. Secondly, there's a Vampire specific ghost named Red Jack mentioned in the 'Mythologies' sourcebook that functions as a Bloody Mary for vampires specifically. He is much, much worse.

Video Games

In the game Ghost Master, there are several ghosts who can be anchored to mirrors, and can scare mortals who look into them.
Paranoia from Castlevania: Dawn of Sorrow lives in the mirrors in its boss room, and jumps out of them to attack Soma. Defeating it lets Soma walk through mirrors.
- Moreover, the first time you fight Paranoia, you really just fight its reflection. Stepping into the next room reveals even more mirrors... and a much larger Paranoia.
- Earlier, in both Aria of Sorrow and Harmony of Dissonance, there were non-boss mirror monsters. In the former, they attacked you while you were standing in front of the mirror. In the latter, they leaped out of mirrors as you passed by them.
Kingdom of Loathing has the Guy Made of Bees, a parody of the Candy Man. If you encounter a mirror in the Haunted Mansion and say "Guy Made of Bees" five times, he appears and attacks you. He's a Hopeless Boss Fight (usually) without a certain item.
At two points in Splatterhouse, Rick walks down a hall of mirrors. Several of them have his reflection turn, climb out of the mirror and attack him.
Saltim a boss from Billy Hatcher is this, he jumps in and out of mirrors trying to attack you and will even try to suck you in.
In Clock Tower: The First Fear, sometimes a hand will reach out of the mirror in the bedroom and try to strangle you when you check it. It's instant death if you haven't learned to reflexively mash the panic button in these types of situations.
In Enchanted Sceptres, there's a dead end with a mirror, which seems "as strong as steel" at first. A Black Knight sometimes appears out of the mirror, and if you smash it then, the knight "shatters into a thousand pieces".
At one point in the original Prince of Persia, your path is suddenly blocked by a mirror. When you jump through it, your reflection separates from you (you re-merge with it near the end of the game).
Subverted with Dark Link in The Legend of Zelda Ocarina of Time. He is Link's reflection who is brought to life through the magic of an enchanted room in the Water Temple.

Web Comics

Spoofed by Xkcd here.
Amy tries to summon Erma this way. It works.

Web Original

In Nan Quest, You can see Henry's head in the mirror behind him. Then he moves out of the way of the mirror. Mirror Henry doesn't. And then he turns around, smiling.
Tragically subverted in the SCP Foundation, with SCP-919. If a person's image is reflected in the mirror for 15 seconds, the reflected image starts moving independently of the person... and begins pleading and begging for the person to not leave, since if the person leaves the reflection dies.
Episode 2 of Gary and His Demons has a mirror monster as the Monster of the Week.

Western Animation

Scooby-Doo and the Ghoul School features some thing that actually refers to itself as a "mirror monster". It does a Mirror Routine with both Scooby and Shaggy, then traps Shaggy in the mirror.
South Park had a version of "Bloody Mary" where, if you say his name three times while looking in a mirror, Biggie Smalls will appear in the room with you (understandably pissed because everyone keeps summoning him while he's trying to get to Satan's Halloween/birthday party).
In an episode of Regular Show called "Jinx", Rigby tries to break his jinx by performing a ritual in front of a mirror. He ends up summoning a demonic reflection from inside a mirror named Ybgir. It's banished back when someone chants its name three times. This has a lot of refrences to the Bloody Mary myth.

Real Life

Kids play a game called "Bloody Mary", chanting the name in front of a mirror in a dark room. Supposedly, her face replaces the reflection in the mirror, and naturally, there are urban legends about kids who kept it up for too long, made Mary angry, and died the next day.
- xkcd played with this by having two mirrors opposite each other.