John Tull has short black hair which he gels back and blue eyes. He wears a sleeveless flannel shirt. He also has a tattoo, of a skull with flames coming out of its eye sockets, on his left shoulder.
Tull is psychotic, vicious, and ruthless. He is a notorious Hitman whose M.O is a point blank shotgun blast to the gut. His only soft spot is for his daughter, Hayley. He is a pervert, as he had sexual fantasies of Samantha, and doesn't cringe to touch Cassandra. He may have an obsession with weapons, because for one of his jobs for the Centurian Biker Gang, he asked to be payed in bullets, guns, and explosives. He used to run with the Garret Clan in the Ozarks for a while.
Hayley is Tull's daughter. He'd do anything for her, he'd kill anyone for who tries to harm her. But most of all, he doesn't want to be apart from her, because he tried to kill himself and Hayley in the plane.
John Tull is killed during the final battle on a private jet. Tull activates a grenade and attempts to kill Samantha and Dave, as well as himself and Hayley. Samantha shoots the airplane door and Tull is sucked out. He is blown apart by the grenade midair.
- John Tull makes a surprise cameo appearance in Endless Summer, Book 1, Chapter 6: if Your Character entered the right password into the computer, they will create a temporal paradox and be thrown violently through other timelines and worlds, one of them being John Tull's trailer, where they narrowly avoid being shot.
- John Tull bears a resemblance to Canadian actor Steven Ogg.
- His crimes include multiple counts of murder and the kidnapping of Cassandra Leigh.