http://scpsandboxwiki.wikidot.com/chubert
In essence, it's something that can make anything you read infect your imagination. You begin to imagine what the footsteps of the thing would sound like, you imagine it's face, and then it shows up and kills you.
Bad idea? Shoot it down with prejudice. If it's bad but salvageable, tell me how. If it's ok but needs work, also tell me how. Thanks.