Complete list of all characters that have appeared in Casper's Scare School's movie, series and comic books.
Creatures[]
Scare School Students[]

The Scare School's "main" students.
- Casper: A friendly ghost, who doesn't like to scare and mistreat anyone, and that's why he was sent to Scare School to get used to the nature of creatures and not be punished for the Valley of the Shadows.
- Mantha: An independent zombie, who entered the Scare School on her own to improve her scares and honor her species name and show how zombies can be just as scary as other creatures.
- Ra: A wealthy Egyptian mummy, member of a royal family, who is always trying to fit in and be on top of everything, as well as trying to impress other students to be better accepted.
- Thatch: A bully and roguish vampire, who is always causing problems for Casper, as well as annoying other students and up to some evil scheme to get along.
- Mickey & Monaco: Two vain and trendy dumb skeleton sisters, who are the only ones on the cheer squad and are always talking about fashion stuff.
- Dummy Girl:A possessed puppet who participates in Thatch's troublemaking clique, is always participating in his pranks, and stands out as the toughest student after him.
- Mosshead: A swamp creature and another member of Thatch's clique, and is always seen following him around and participating in most of his plans, though he also gets along well with Casper's group.
- Slither: A snake-like creature and the third member in Thatch's clique, who is generally the calmest and most sensible, although he still loves to participate in Thatch's tricks.
- Wolfie: A somewhat insecure werewolf, who is a loyal friend to Casper's group and is always available to help them when they need it and excels as a good scarer at school.
- Quasi: A hunchbacked creature who, in addition to studying, is also responsible for doing activities for the teachers and principals, including ringing the bell, which he hates to do.
- Harpy: A half-human, half-bird creature, who is known to be the clumsiest girl in school, and usually only communicates by cackling, and sometimes also gets into Thatch's plans.
- Pumpkinhead: A scarecrow-like creature, who is one of the loneliest and most innocent students in the school, and his only friend is a simple little pumpkin.
- Blodge: A green blob-like creature, who often participates in Casper's schemes, being a very useful friend to him, and his greatest desire is to be a famous DJ.
- Triclops: A shy and unsocial Three Eyes creature, and is a big target of teasing and bullying by other students, including Thatch.
- Flyboy: A fly creature that was once a human in the past before an accident in his father's lab, and is one of the kindest and most bullied students at Scare School.
- Frankie: A Franken creature, the son of the school's gym teacher, who is always scolded by the teachers for being late to class, and was Mantha's dancing partner at the dance in "The Last Dance".
- Gill: A fish creature, capable of breathing both in water and on land, who was first seen thanking Casper for saving the students from the Sea Monster.
- Drip: A small red creature shaped like a droplet, he took part in the school's first excursion to Deedstown, where he was seen trying to scare Jimmy but failed.
- Brainiac: A creature with a body made entirely from a large brain, it appears to be a close friend of Flyboy.
- Student Witches: An extensive group of little witches who attend Scare School during the events of the film, but are absent from the series.
- Unknown Purple Fur Student: A furry creature reminiscent of a primate and apparently one of the strongest students at Scare School.
- Unknown Horned Yellow Student: A demon-like creature with yellow fur and horns. He was one of the students that Thatch teased about on Cappy's ship.
- Unknown Crawling Student with Illicium: A monstrous creature that somewhat resembles an anglerfish. He was Wolfie's tour partner in "Grimly Day".
- Unknown Stretched Crawling Student: A tall, orange monster that resembles some kind of giant worm.
- Unknown Crawling Student with Garbage Can: A green creature resembling a blob monster, with its face covered by a garbage can, it was one of the creatures formerly banished to the valley of shadows.
- Unknown Cyan Blue Student: A large cyan blue monster with reddish eyes that looks like some sort of gargoyle.
- Unknown One-Eyed Student: One of those formerly banished to the valley of shadows and who now attend Scare School. He is a blue monster that resembles a cyclops, having only one eye.
- Unknown Marine Student: Some sort of fish creature that resembles a monstrous cherry.
- Unknown Gremlin Student: It is a gremlin-like creature with light purple fur and a small horn on top of her head.
- Unknown Fire Spitting Student: It is a thin and small purple creature that is capable of sneezing fire.
- Unknown Skeleton Student: One of those banished to the valley of shadows previously. It's a living skeleton with a medieval helmet.
- Unknown Hooded Student: A mysterious creature whose face is hidden by the hood of his clothing.
- Unknown Two-Faced Student: An orange creature wearing a school-type uniform, and has a pair of faces, one happy and one angry.
Scare School Staff[]
- Alder & Dash: A two-headed crawling monster and the two executioner headmasters of Scare School, who are obsessed with anything evil and love to punish their students harshly.
- Thurdigree Burns: A dragon who works at Scare School as the science teacher, and detests Casper for his attitude of always correcting him in his classes.
- Frankengymteacher: A Franken Creature and the Scare School's gym and geography teacher, who is not very smart but generally peaceful, and has a crush on the history teacher.
- Hedy Hopper: A meditative head who works as a history teacher, who is quite obsessed with the subject she teaches and also has a crush on Frankengymteacher.
- The Gargoyles: The main responsible for cleaning, janitorial, assessment of scares and safety of the principals. Despite their loyalty to their bosses, they also get into mischief from time to time.
- The Nurse: She is the school's only nurse and the most feared member of the school's faculty, mainly because of her drastic measures to take care of students.
- Mad-Dog McSneer: The Scare School's night watchman, who was once well known in underworld history before taking this job, something he keeps a secret.
- Calc Lizard: A math-expert talking lizard who is responsible for guarding the library and taking care of students during staff meetings.
- The Cafeteria Thing: A purple creature with several tentacles that serves lunch and snacks to students in the cafeteria, which is generally calm, but can get quite violent when disturbed.
Other[]
- Stretch:
- Fatso:
- Stinkie:
- Ghostly trio's Aunt:
- Ra's Family:
- Mantha's Family:
- Thatch's Parents:
- Flyboy's Father:
- Sea Monster:
- Scare Center hosts:
- Razznik:
- Master Blister:
- Frankengymteacher Clone:
- Frankenleftovers:
- Bakora:
- Veggie Man:
- Love Dragons:
- Goo:
Humans ("Fleshies")[]
Bradley Family[]
Deedstown Residents[]
- Norman #1:
- Norman #2:
- Bethica:
- Freddie:
- Freddie's Mother:
- Police Man:
- Dr. Bungleman:
- Mr. Crowley:
- Grendall Spinks:
- Daisy:
- Other Citizens:
Valley of the Shadows Residents[]
- Aunt Spitzy:
- Murray & Belle:
- Other Residents:
- Casper's Shadow: