Trivia: Notably, the previews for this film (and several other sequels in the series) contained footage not seen in the finished movie. The previews were often made primarily of footage from alternate and deleted scenes. The producers and directors hinted that this was done to help keep the story secret, despite being a bit shady on their part.
Trivia: Originally, Kevin Greutert, who edited the first five "Saw" movies and also directed "Saw VI" and "Saw 3D," was attached to direct. However, Lionsgate enacted a contractual clause to remove him from the film. While an exact reason was never given, it has been widely speculated that this was done because the "Paranormal Activity" movies were the only direct competition for the "Saw" series at the box office.
Chosen answer: It's the demon.
Manky