It can manipulate weak-willed people, making them indifferent to the horrific events that unfold, or even serve as accomplices. In the novel, It claims that its true name is Robert "Bob" Gray, but decided to be named It . Throughout the book, It is generally referred to as male, usually appearing as Pennywise.

Pennywise was responsible for the explosion at the Kitchener Iron Works that killed 108 people, including 88 children. IT can also be awakened by an act of violence on top of Pennywise's 27-30 year cycle.