John Cavil (Number One) is a fictional character and the main antagonist from the re-imagined Battlestar Galactica television series (2004), portrayed by Dean Stockwell. In the fourth-season episode "Six of One", Cavil's model number was revealed as Number One. He is a humanoid Cylon model that appears as a highly rational, eccentric man in his late-sixties. The Cavils have a heavy sarcastic demeanor and a sense of humor. They take neither religion nor death seriously and are the only atheist Cylon model. A Cavil is first seen aboard the Galactica assuming the role of a priest, offering spiritual guidance, and going by the name "Brother Cavil."