Reginald P. Linux
"I'm being terrorized! I'm being terrorized by this horrible doll!"
- Agent Scully: Linux constantly scoffs at Officer Cop's insistence that the doom house is real and that he should move, always repeating the words "doom house" with a sense of baffled bemusement and confusion.
- Awesome McCool Name
- Dark and Troubled Past: Reginald's wife died some time before the story takes place, and Reginald has been feeling depressed because of it ever since.
- The Determinator: No matter how much Reginald is terrorized by the evil of the doom house or advised by the police officer to leave the residence, he is determined to stay there and is eventually able to work out a gentleman's agreement with the house's horrors.
- Freak Out: Linux's inability to understand the anomalous nature of the Creepy Doll and his realization that the doll cannot be removed from the house or destroyed causes him to have a very epic one of these.
- Limited Wardrobe: The story takes place over the course of a few days and nights, but Reginald is only ever seen wearing a Cubivore T-shirt and black shorts, occasionally accessorized with a rayon Hawaiian shirt and a baseball cap (again, only one type of each item).
- Mysterious Middle Initial: P.
- Nice Hat: Reginald's baseball cap which he wears to support his favorite sports franchise.
- Ridiculously Average Guy: He's just an ordinary guy, caught up in an unordinary situation.
- Sole Survivor
Police Officer (a.k.a. Officer Cop) / The Terrorist
"Reginald P. Linux, I heard you needed a cop."
- Agent Mulder: When Officer Cop first arrives at the house, he is quick to conclude that a paranormal occurrence is the only possible explanation and that the house must be a doom house.
- Appeal to Authority: Constantly reminds Reginald after everything he does or suggests should be done that he is a cop and trained as such, but this is just a lie intended to win over Reginald's trust.
- Big Bad
- Detective Mole: He arrives at the doom house to help Reginald P. Linux and turns out to be the one responsible for the horror Linux is experiencing.
- Does Not Like Shoes: Never wears them.
- Face–Heel Turn: Initially thought to be a friendly police officer, he turns out to be a terrorist.
- A Fate Worse Than Death: Being bored.
- Great Detective: Is able to recognize a doom house after Sherlock Scanning plastic baggies.
- Limited Wardrobe: Only wears a plain navy T-shirt and jeans. No shoes.
- No Name Given: His name is Officer Cop, as revealed in the Japanese anime series, but in the original Doom House this character is unnamed and only identified as "Police Officer" in the credits.
- Stepford Smiler: With blank, vacant eyes and muted emotions, his constant grinning appears all the more unsettling.
- Terrorist Without A Cause: His focus is to harass a single person into leaving a house so he could reclaim a "Terrorist Burial Camp".
"You're going to die! I'm gonna cut your hair, and put it in a bowl!"
- Blue and Orange Morality: Its actions and motivations cannot be understood through human logic or reasoning, but over time, Linux and the doll are somehow able to work out a "gentlemen's agreement", the exact terms of which are unknown.
- Clingy MacGuffin: It's an "odd-looking figurine" which haunts the doom house and constantly appears near Linux, even after he grinds it up in the garbage disposal.
- Creepy Doll: Just look at that thing!
- Cut His Heart Out with a Spoon: It seeks to cut off hair and place it within the confines of a bowl.
- Evil Phone: The device through which the doll communicates with occupants of the doom house.
- Fan Nickname: "Odd-Looking Figurine"
- Offscreen Teleportation: How it moves around the doom house.
- Red Herring: At first, we're supposed to think that Linux is being terrorized by a horrible doll, but he is, in fact, being terrorized by a terrorist.
- The Speechless: Only heard speaking once, off camera and over a phone.
Reginald P. Linux's Wife
- Backstory: Died in a tragic Noodle Incident.
- The Lost Lenore: For Reginald.
- Plot-Triggering Death: Her death is the catalyst for everything that follows afterward.
- Posthumous Character