Timmy is a child whose mother died in a car crash.
History
He lived at Sonny's house for boys for over a year. Timmy's mother died in a car crash/fire after pushing Timmy out of the burning car and saving his life. After his mother died, he ran to the woods and hid in an abandoned building. Timmy's sadness for his mother's death caused her to be tied to Earth, and she returned as a ghost.
During his stay at Sonny's farm, Timmy's mother began killing or maiming any person whom she saw as a threat to him. When the Winchesters become involved and eventually found out, they assumed that Timmy's action figure was the object his mother tied herself to and destroyed it, only to learn that she had tied herself to Timmy. To enable his mother to move on, Timmy was forced to let her go and assure her that he would be okay.