A lot of TV shows had characters who were never seen on screen except for maybe hearing their voice or seeing their back or hands or who were often mentioned but never seen Wilson - Home Improvement Charlie - Charlie's Angels George Steinbrenner - Seinfeld Vera Peterson - Cheers Juanita - Andy Griffith Show Sarah - Andy Griffith Show Orson - Mork From Ork Ugly Naked Guy - Friends Carlton the Doorman - Rhoda Maris Crane - Fraser Red John - The Mentalist Mammy 2 Shoes - Tom and Jerry Columbo's Wife - Columbo Robin Masters - Magnum PI Mrs. Wallowicz - Big Bang Theory Adults - Peanuts Specials John Beresford Tipton - The Millionaire Fearless Leader - Rocky and Bullwinkle
On the old TV western series Maverick both Bret and Bart Maverick frequently referred to their "Old Pappy." Sage advice such as "My Old Pappy told me never to play poker with a man wearing a pinky ring." Stuff like that. Old Pappy was never seen or heard in the series. Many years later they made a made for TV movie Maverick with James Garner and Jack Kelly reprising their old roles. In the movie there as an actor playing the role of Old Pappy Maverick who had a big part in the plot.
No adults ever were seen. Even their voices were just some kind of wa wa wa musical notes. The closest to being seen was Lucy and Linus's mother when their little brother Rerun was riding on the back of her on a bicycle.