Donald Roeser (born November 12, 1947), known by his stage name Buck Dharma, is an American guitarist, singer, and songwriter. He is the sole constant member of hard rock band Blue Öyster Cult since the group's formation in 1967. He wrote and sang vocals on several of the band's best-known hits, including "(Don't Fear) The Reaper", "Godzilla" and "Burnin' for You".