Robert "Bob" Brunner (August 3, 1934 – October 28, 2012) was an American screenwriter, film producer, and television producer. He frequently collaborated in film and television with Garry Marshall, the creator of Happy Days. Brunner is credited with creating the "Fonzie" nickname for Henry Winkler's character, Arthur Fonzarelli, on Happy Days. He also created one of Fonzie's key catchphrases, "Sit on it."