Tommy Frazer
The main protagonist, and the new student at Bell Valley Middle School. He, along with his new friend Ben, end up being sent to Grayworld, and they need to escape.
- All Love Is Unrequited: He offhandedly mentions at one point that he sort of likes Thalia, and wants to impress her. But because she chooses to stay in Grayworld, he doesn't end up together with her.
- Apologises a Lot: He constantly apologizes to people for the littlest mistakes he makes, mainly because he doesn't want to get off to a bad start at his new school.
- Big Damn Hero: When Greta was stealing Thalia's lipstick in class and teasing her with it to the point that Thalia was furiously bursting into tears, nobody else stood up to defend her. Except Tommy, who felt sympathetic towards her and fought Greta over the lipstick to give back to her. He even lampshades that it's "hero time" for him.
- Determinator: He keeps trying to get back to the real world by escaping Grayworld, even when it looks as if that would be impossible.
- Fish out of Water: He and Ben are very confused around Grayworld, not having been in a world devoid of color. It doesn't help that the first citizens of the place hassle them because they haven't seen vibrant color in 50 years. And that's when they start to lose color themselves, making Tommy and Ben freak out and want to go back to the real world.
- I Just Want to Have Friends: He was barely able to say goodbye to his friends at his old school before being sent to this new one. Therefore, he seized the first chances he can get at making new friends, which included volunteering for painting the gym and decorating the school dance.
- The Klutz: He frequently stumbles over things while walking around his new school, which almost gets him beaten up by Greta when he trips over her, causing her head to knock to the floor.
- Messy Hair: Has wild black hair that he has trouble combing and slicking back, much to his embarrassment.
- Oh, Crap!: He and Ben manage to get back to the real world, only for their teacher to tell them to get in line with the rest of his class for a photo. Right before it is taken, he hears that the photographer is Mr. Chameleon, the person who sent the class of 1947 to Grayworld in the first place! Tommy frantically cries out to stop the photoshoot, but the camera flashes.
- Too Dumb to Live: He and Ben have to go to the third floor for more decorations. Instead of taking the stairs as Ben suggests, Tommy decides to have them take the elevator in the basement. You know, a rickety old one that looks as if it hasn't been used in many years and could break easily. Granted, it doesn't exactly lead to that kind of trouble, but Tommy should have known better.
- Tragic Keepsake: He got a handlighter from his grandfather a few weeks before he died, and so he holds onto it dearly, even bringing it to school even though he knows that it is probably against the rules. This becomes a Chekhov's Gun when he uses it to create a colorful fire in Grayworld to frighten away the savage native students of 1947.
- Uncertain Doom: He is probably sent back to Grayworld by Mr. Chameleon, along with the rest of his class. However, if they have an item of color that can get them back to the real world, such as lipstick, he and his class could do so..
Thalia Halpert-Rodis
A student at Bell Valley Middle School who becomes friends with Tommy Frazer. Thalia gets picked on because she wears a lot of make-up, to the point that she nearly has a nervous breakdown when someone steals her lipstick. She was part of the original Bell Valley Middle School class of 1947, the one sent into Grayworld by Mr. Chameleon. Thalia was one of a few who retained their sanity, and discovered by accident a way to escape back into the color world, only she is now permanently gray.
- Adaptation Dye-Job: In Goosebumps Horrortown, her natural hair color is purple instead of blonde.
- Berserk Button: Don't ever try to steal her lipstick or her make-up. Justified since it's all that's keeping her true form hidden.
- Broken Bird: While she stayed sane after all those years, she feels so out of touch with the modern world she'd rather spend the rest of her life trapped in a colorless, photo-like dimension with the rest of her friends.
- Chekhov's Gun: Her lipstick. When she was still in Grayworld, she discovered that a lipstick tube buried in her purse somehow retained its color. She started drawing with it and was shocked to see the color had eaten away at the walls and opened a portal back to the real world. Thalia went through, but the hole closed up before she could get her friends. When she makes it back to Grayworld, she uses the lipstick to help Tommy and Ben escape.
- Going Native: The stress of constantly hiding her gray visage, being constantly picked on by the other kids because of her "obsession" with make-up, and just generally feeling out of place because of how different the world is makes Thalia realize the only place she belongs now is Grayworld.
- I Choose to Stay: After helping Tommy and Ben return to the color world, she stays behind because she doesn't think she belongs outside of Grayworld anymore. The rest of her friends end up realizing the same is said for them.
- Locked into Strangeness: She's completely gray, and wears so much make-up to hide her gray skin and hair. Like the rest of the class, being in Grayworld stopped her physical growth.
- Older Than They Look: She should be in her sixties by now, considering she was a member of the 1947 class.
- Raincoat of Horror: Her attire in the 2018 game is a yellow raincoat.
- Skin-Tone Disguise: Thalia is frequently depicted as wearing copious amounts of makeup, lipstick and concealers on her, to the point where it's impractical and the other students would make fun of her for it. As it turns out, she was actually one of the Class of 1947, sent to the Grayworld and escaping from it after she's stuck for 50 years, where her make-up is used to hide the fact that she's Deliberately Monochrome after the Grayworld drained all the real-world colors from her body.
- Uncanny Valley Make Up: She wears so much of it that this is the end result.
- Walking Spoiler: Unlike most examples in Goosebumps canon though, she's not the villain.
The Grayworld Children
A terrifying clan of mutant children that reside in "Grayworld", a dimension rendered permanently gray. They roam the lonely streets, searching for unlucky visitors to convert to their clan. What's worse, they all used to be normal kids.
- Adaptational Villainy: In the book only a select few kids in the class had gone native. In Horrortown, they are all villains although some are at least a bit nicer at first.
- And I Must Scream: Driven insane by years trapped in the Black and White world.
- Assimilation Plot: They desire nothing more but to rid anything-and anyone they see of color, turning them over to "the gray". And now,the movie implies they'll be taking this to our world!
- Creepy Child: Holy shit. The "Oil spewing" ceremony speaks for itself.
- Cult: One composed of insane children. There's a reason this entry is considered one of the darkest in the series.
- Driven to Madness: They slowly lost their minds over the decades they spent trapped in Grayworld, and only a handful of the kids managed to retain their sanity.
- Knight of Cerebus: Not only are they not hammy or campy antagonists, but the reveal of what they are turns The Haunted School into one of the darkest and tragic books in the entire franchise.
- Madness Mantra: "Turn. Turn to the Gray!"
- Tragic Monster: Every one of these mutants were once perfectly normal schoolchildren who attended Bell Valley in 1947. Than the evil photographer Mister Chameleon sent them to Grayworld and it changed them forever.
- Trapped in Another World: For so long now they've given up hope of rescue.
- Weakened by the Light: They flee at the sight of any light or color. As it turns out, this weakens the fabric of the other dimension and allows an escape.
Mumler Chameleon
The evil photographer who trapped the kids in the Grayworld with his magic camera to start with.
- Ascended Extra: He has a much larger role in Goosebumps HorrorTown
- Beard of Evil: Goosebumps Horrortown gives him a very bushy grey beard and mustache.
- Child Hater: Supposedly hated kids, but was the only photographer available.
- Evil Old Folks: Still around by the end of the story, by which point, he should be in his 70's at least.
- Evil Sorcerer: Obviously some kind of magic person, as he was somehow able to make a magic camera.
- Ironic Name: Chameleons can change color, and he was able to trap people in a world with no color. Lampshaded by one of the kids trapped in Grayworld.
- Irrational Hatred: Neither the story nor Horrortown give any explanation for why he hates children so much.
- Karma Houdini: He gets no comeuppance for trapping an entire class of innocent children in another dimension where they are doomed to spend eternity and go insane.
- Meaningful Name: In Horrortown, at least. His name, "Mumler", is a reference to William H. Mumler
, the inventor of spirit photography. - Named by the Adaptation: Goosebumps Horrortown reveals that his first name is Mumler.
- Posthumous Character: Averted; he's somehow still alive in the present and takes the kid's picture in the Twist Ending.
- Reptiles Are Abhorrent: He's named after a lizard and is evil.
- Red and Black and Evil All Over: While his appearance isn't described in the book, Horrortown has him wearing an old timey black suit and red glasses.
- Red Eyes, Take Warning: His design in Goosebumps Horrortown has red glasses.
- Scary Shiny Glasses: His design in Goosebumps Horrortown gives him a very shiny pair of red glasses.
