Tom Cullen is a mentally handicapped man from May, Oklahoma, where he lived with his mother and borderline-abusive father Don.
Several years before the superflu outbreak, Don Cullen abandoned his family to run away with a cocktail waitress named DeeDee Packalotte, a fact Tom frequently mentions.
Tom is of Scandinavian background and appears youthful, though at the time of the plague he is actually in his mid-forties. He works as a handyman for a neighboring farmer called Norbutt, performing simple odd jobs and manual labor. Tom is barely literate and had to make superhuman efforts in formal education. When he was 16 years old, despite his best efforts, he only earned certification equivalent to Grade 3.
Cheerful, good-natured and helpful, Tom has a childlike personality. His speech pattern includes a number of verbal tics: repetition, the phrases "M-O-O-N spells (x)", and frequent interjections of mild oaths like "Laws yes!" and "didn't it/they just?"
In order to make simple deductive leaps, Tom has developed a unique ability to hypnotize himself. Entering this altered state of consciousness leaves him temporarily slack-jawed and limp, which formerly caused him to be a figure of ridicule in town and greatly annoyed his father; however, for Tom these were "instances of nearly normal thinking." His ability to make connections by going within himself is cited as evidence that his mental handicap is not actually very severe.
Tom picks up the hobby of decorating as a medium of self-expression, which would probably be considered "outsider art". He first decorates the abandoned town of May, then later his house in Boulder: chiefly he collects and arranges a variety of props, such as mannequins, lawn ornaments, advertising posters, and taxidermied animals.
Tom loses his mother to the superflu, and ends up being the last living resident of the town of May.
He is the first plague survivor Nick Andros encounters after leaving Shoyo, Arkansas. The two become traveling companions and close friends, although they initially have difficulty communicating. When dealing with non-deaf people, Nick has developed the habit of "talking" via scribbled notes; as Tom cannot read, Nick is forced to pantomime a lot (he can, however, read Tom's lips.)
Thus, for the first leg of their journey together Tom does not even know Nick's name, even though Tom's quick reaction to an approaching tornado manages to save them both.
Boulder Free Zone
He is given his instructions via hypnosis; while under trance, Tom startles the Committee by displaying both intelligence, and heightened psychic perception. This aspect of his personality refers to itself as "God's Tom" — or, in Stuart Redman's words, "the man forever denied".
Tom is spotted in Las Vegas by fellow spy Dayna Jurgens, but she suicides rather than give up his name to Flagg. He is, however, positively identified by the spiteful Julie Lawry, and manages to flee just ahead of apprehension by Flagg's henchmen, escaping the destruction of the city itself.
In the Utah badlands he encounters Stu Redman, waylaid by a broken leg and dying from exposure; together they reach shelter in Green River, Utah. With the aid of Nick's ghost, Tom saves Stu's life by treating his pneumonia and spends several weeks nursing him back to health.
Tom and Stu winter for a month in Grand Junction, Colorado and finally return to the Boulder Free Zone.