Substitute (2018)

Substitute is a Creepypasta series that tells the story of Clyde as he recounts his experience with a strange substitute teacher he had in 6th Grade named Mr. Cotard. What started off as an unusual substitute turned into a living nightmare as Clyde and his friends are taken to the Headquarters of a strange organization called the TTC, whose sole goal is to teach them that everything they know isn't real.