Spoilers Off applies to all Nightmare Fuel pages, so all spoilers are unmarked. You Have Been Warned!
- The Polybius video starts with a disclaimer mentioning how disturbing the topics brought up in said video are, and then quickly dives into unsettling visuals, such as blood dripping down images at certain parts. The topics of the video itself aren't much better, as he discusses the true purpose of Polybius, being a secret government experiment covered up after cases of memory loss and other conditions became widespread.
- MatPat's gallery of executions by elephant in "Why Mario is Mental, Part 2". He tries to give the viewer a feel of what it's like to be crushed alive by an elephant - all accompanied by artistic depictions. He does to to explain just how painful Mario's preferred method of killing really is.
- His two parts Doki Doki Literature Club! video is noticably glitchy and seemingly haunted by Monika, who even speaks (fully voiced to boot) at a few points. The first part has his catchphrase be corrupted into a Broken Record that keeps saying Just Monika and the second part, after theorizing that the true threat (or at least the threat of Team Salvato's upcoming game) is none other than Yuri, has her seemingly killing MatPat as he's saying his catchphrase before going after the viewer!
- The Petscop videos. MAN, OH MAN. The first was bad enough, with him describing in vivid detail the real-life death by suffocation of Candace Newmaker during a "rebirthing" attachment therapy session. But the second is even worse, as it cranks the creepy editing, surprise jumpscares and glitching from the Doki Doki episodes to a whole new level and uncovers what seems to be a series of murders and abuse caused by a man named Marvin and how he's the shadow man.
- His description of what the real effects of Operation: Cinder would be. Storms wouldn't be the worst of it. The plasma would heat the sky, and to quote the video: "A warmth that would gradually grow hotter, and hotter, until you found yourself boiling alive, baked to death like you were in the world's largest convection oven, because that's actually where you would be."
- The Try to Fall Asleep theory, delving into nightmare deaths and hallucinations, including two lovely anecdotes and real-life deaths. If that wasn't unnerving enough, Mat then theorises that Dr Richard Norberg, the therapist who advised the protagonist John Herrin to sleep it off, is a Psycho Psychologist with ulterior motives, with the doctor cutout gaining a black Slasher Smile and reaching out to John Herrin with white gloves. As the episode ends, the camera zooms in on Norberg as his eyes turn red.
- The ending of the theory based around the "Bob" mod for Friday Night Funkin'. The whole theory discusses a unsettling ARG where a man created a self-aware AI, which murdered him and his wife and disfigured and rendered his young daughter comatose, all using a mysterious black ooze. MatPat ends the video discussing the AI, Bob, when it attacks and corrupts him with the black goo. MatPat is heard gasping and struggling to breathe through the outro, as Bob's hyper-realistic eyes fill the screen and it gloats about killing the host. Even the sponsorship segment after the outro is styled to look like MatPat's funeral, with his friends and family mourning in the audience.
