Thomas Hagen is a fictional character in Mario Puzo's 1969 novel The Godfather and Francis Ford Coppola's films The Godfather (1972) and The Godfather Part II (1974). He is portrayed by Robert Duvall in the films. He also appears in the Mark Winegardner sequel novels The Godfather Returns and The Godfather's Revenge, as well as Ed Falco's novel...