Square One Television/YMMV


 * Nightmare Fuel - Mr. Glitch was an anthropomorphic tornado who would eat Mathman if he got a question wrong.
 * And once for absolutely no reason at all. That time, he filled the whole damn screen.
 * There was also one time when the roles were reversed and Mr. Glitch got to run the maze. In the end, after his (inevitable) failure, Mathman ate him one bite at a time.
 * And let's not forget the immense creepiness of the battles between the pluses and minuses... A visceral testament to the simplicity of arithmetic and the futility and horrors of war.
 * This troper found the "Ghost of a Chance" video very creepy and had to leave the room whenever it appeared. The whole concept of a pizza delivery boy getting trapped in a haunted house forever, unless he gets very lucky making a series of random guesses (to teach probability) is nightmarish enough, but then you have real footage of thousands of worms crawling over each other and an endless hallway with "EXIT?" signs over an endless number of doors. He picks the wrong one.
 * Memetic Mutation - One One Two Three
 * Five Eureka!
 * What Do You Mean It's for Kids?: Some of the Mathnet segments were particularly dark at times, particularly "The View from the Rear Terrace", which has Kate Monday bound and gagged in her apartment with her neighbor's homemade bomb, and "The Case of the Masked Avenger", which has the mob blackmailing a wrestler over an opponent's death 20 years ago.