For the radio program, Bergen developed other characters, notably the slow-witted Mortimer Snerd and the man-hungry Effie Klinker. The star remained Charlie, who was always presented as a highly precocious child (albeit in top hat, cape, and monocle)—a debonair, girl-crazy, child-about-town. As a child, and a wooden one at that, Charlie could get away with double entendres which were otherwise impossible under broadcast standards of the time.

Edgar John Bergen (born Edgar John Berggren; February 16, 1903 – September 30, 1978) was an American actor, comedian, vaudevillian and radio performer, best known for his proficiency in ventriloquism and his characters Charlie McCarthy and Mortimer Snerd. He was the father of actress Candice Bergen. Bergen's skill as an entertainer, especially his characterization of Charlie, carried the show (many recordings of which have survived). This episode from November 16, 1941 features actress Gene Tierney and vocalist Maxine Gray with the Ray Nobel Orchestra.