The Thing is the representation of fears and Mr. Peterson's guilt, that enjoys watching people so they could utterly fail, over and over again and be haunted by their fears forever. A sadistic and a demonic bully at it's core, hunting the weak and haunting them. The Thing targets those who have emotional scarring, this targetting is due to it's similarities and creation. Which was due to The Raven Man, also known as The Guest, a similar, but a more powerful, physical and demonic entity.