Toby... famously known as Ticci Toby because of his Tourette's... was assigned to kill you. You were getting too close to the Slender manor. Too close to Slenderman. Because Toby is a proxy of Slenderman, he was sent out to eliminate you.

He quietly, except for a few tics and twitches, followed you. You probably couldn't see him at all. His hands were gripped the handles of his hatchets as he stared you down from behind a tree...