David Brenner appeared several times on Johnny Carson 's late - night show . He was 78 . Brenner started out in television documentaries . ` ` Knowing David , he 's now making the world laugh , '' Joan Rivers tweets .
David Brenner appeared several times on Johnny Carson 's late - night show . Brenner started out in television documentaries . ` ` Knowing David , he 's now making the world laugh , '' Joan Rivers tweets .