This resource pack is for The Knocker mod. You will need to have it installed, otherwise this has no effect on the game. And no, you do not need Optifine for this to work (hooray)! The Knocker is also currently only available for 1.19.2, 1.20.1, 1.21.1 and 1.21.8, effectively locking this resource pack to those respective versions.
With months of unexplained murders across many villages and rural houses, locals and travelers are advised to keep watch for the possible suspect. He is described to have "cold, crazy eyes with burnt patches around them, black hair, pale skin with a carved smile on his face, and a filthy, white hoodie". Witnesses have reported hearing knocking on their doors and windows at night, finding their doors wide open, and even spotting deceased animals on their property. With the authorities still unable to trace the suspect's whereabouts, it is heavily advised to contact them, rather then to engage in combat with the suspect. 
This resource pack revives the old internet Creepypasta "Jeff the Killer" to Minecraft, using M_Productions (Ma_Do)'s creation "The Knocker" as a vehicle to bring this idea to life.
