Professor Mizzy (1 episode, 2001)
James Edwards (1 episode, 2000)
Dr. Greenburg (2 episodes, 1990-1991)
Marty Gradinger / ... (3 episodes, 1987-1993)
Man (segment "The Library") 1 episode, 1986
Mr. Lawler / ... (3 episodes, 1984-1986)
Dr. Lowell (1 episode, 1987)
Mr. Secretary (3 episodes, 1989)
Howard Gabriel / ... (4 episodes, 1976-1981)
Harry Moss (1 episode, 1977)
Jim Richardson (unknown episodes, 1978)