John Valentine is a character in The Twilight Zone movie.
He is the main character of the fourth segment nightmare at 20,000 feet. He is first seen in the airplane bathroom recovering from a panic attack, upon sitting down he notices the Gremlin on the wing of the plane. He attempts to show people the Gremlin but they don't believe him. He finally snaps, taking a gun from a sleeping Air Marshal and shooting the window causing de-pressurisation. The plane is forced to make an emergency landing, the gremlin grabs John's face and scowls him before flying off into the sky. On the ground, John is placed in a straight jacket and hauled away into an ambulance. Meanwhile, the maintenance crew notice claw marks on the wing of the plane.