Hitman, over 4m tall. He wears an eyepatch over his left eye, has yellow sclera, and black, slightly curled horns with black eyes. He wears a black cap and is dressed entirely in black. He is said to be incredibly strong and proficient with various weapons. He planned to kill the teachers because a bounty was placed on them.

Bat beastman, security guard, 518cm. He uses polite speech and is kind yet timid. He has bat wings and ears, and since his left eye is a monitor, he can display emotions with emoticons. He can fuse a gun barrel to his left arm. He is in a same-sex marriage with Hotchkiss. He is on the students' side and likes s'mores. However, he becomes monstrously cruel toward intruders. He has long white hair tied back and a long black tail. This guy is insanely strong. He can also fuse a laser gun to his left arm.

298cm, compass fused to left arm, math teacher. One of the top three teachers (along with Thavel and Bloomie), she loves Oreos. She kills students who fail with her compass. She has a playful side and is in a relationship with Compass. She is strong enough to break down doors.

190cm, weapon-type human, assistant math teacher. Looks very similar to Circle but they are not siblings. Usually takes the form of a compass with blue eyes. Likes KitKats.

Mr. Eclipse: Wears Anubis decorations, has a cheerful personality, and is a disco dance teacher. He is a shadow person like Sieze and once had his heart ripped out by Sieze. He doesn't get along with Hinata. Mr. Foxtrot: His left eye is an X, but when he gets angry, it tears open to reveal a black sclera and red pupil. He is a cheerful, 4m tall, playful dance teacher with flexible joints. He snaps the bodies of failing students. Mr. Strontium: Wears a black gas mask and has long black hair. He is quiet, polite, and Bloomie's assistant. He is a dragon beastman but lost most of his power after losing his left eye. His real name is Benedict. He doesn't really kill students. He uses an alias to hide from his father. 253cm. Mr. Hotchkiss: Craft teacher. His left eye is a letter and his left arm is a stapler. He kills failing students and has long black hair. 3m. Mr. Broomire: Janitor. He hates his job and kills students who litter. His left arm is a vacuum cleaner. He likes Cledor and is short-tempered. 3m. Mr. Tron: A cute robot whose true form is a blue slime. Engineering teacher. Mr. Demi: Has a crush on Sasha. A timid music teacher. 180cm. Mr. Sieze: Anatomy teacher. Carries large scissors, is obsessed with Barrel, and is a bit of a madman. 2m. Mr. Vane: Has a red halo and a pair of wings, appearing like a mix of a demon and an angel. He is the vice-principal and, unlike the principal, is kind and polite. 281cm. Mr. Eugene: PE teacher. Seems to have a gentle personality. Doesn't appear to kill students. His left arm is a golf club.

Miss Elbara: School nurse. Has red eyes and a calm personality. Highly skilled, even capable of reviving dead students. 170cm. Miss Ashatchu: Owner of the school cafe. Kind and energetic. Can make 12 types of drinks, including Americanos. 170cm. Miss Bloomie: Has a utility knife fused to her left arm. Black hair, the shortest among the teachers. Science teacher. 168cm. Stabs failing students to death. Miss Thavel: Language teacher with creature-like hands. Has three alphabet blocks on her head and deer antlers. Playful. Rips failing students apart. 251cm. Miss Bogurs: Electric snake beastman. Swimming teacher with sharp blue eyes and a red safety helmet. Very irritable. 330cm. Miss Sasha: Her left eye is a green book. Art teacher and kindergarten teacher. A kind teacher who doesn't kill students. Miss Hinata: Religion teacher and kindergarten teacher. The tallest female teacher at 4m. Usually has her eyes closed, but is said to be most terrifying when she opens them. Carries sun decorations and a spear; she stabs anyone who messes with the kindergarteners or fails. Miss Cledor: Librarian. Quiet. Her left arm is a keychain and her left eye is a lock. Kills students who talk and likes Broomire. 2m.

Principal, 189cm. Calm with two horns, though one is broken. Caffeine addict. Authoritative, but completely ignores the murders committed by the teachers. Not a monster, but the teachers cannot touch her.

Twins, safety officers, 281cm. Redhalt: Male, the older brother. Has red sclera and long black hair. Realistic and blunt. Wears a white cap and has white skin. Greenmile: Male, the younger brother. Has green sclera and long black hair. Energetic and playful. Wears a black cap and has black skin. When angry, their hair burns like flames. They move around on roller skates. They can transform their left arms into gun barrels. They hate bad students.