Jeff the Killer, born Jeffery Woods, is the titular main protagonist turned to the main antagonist of the 2011 (and 2015 revamped) Creepypasta story of the same title "Jeff the Killer" and "Jeff the Killer 2015"
He is an adolescent serial killer and registered Creepypasta. He was disfigured after being set on fire while fighting a gang of bullies and lost his sanity after witnessing his "new" and "beautiful" face.
The time didn't matter to you, all you knew was that you couldn't sleep. Tossing on a sweatshirt you left your house to go on a walk. You put your headphones in/on and turned on your favorite playlist.
Walking for about 30 minutes, you met up with the park in your area, you walk over and sit down on the swing. This is when you finally get that shiver down your spine, like you're being watched. You whip your head up and that's when you see him. A figure only standing about 20 yards away.