He was also an alum of The Bob Newhart Show

Jack Riley, an alum of The Bob Newhart Show and the voice of Stu Pickles on Rugrats, has died at the age of 80. The actor died from pneumonia in Los Angeles early Friday morning, his representative Paul Doherty tells Entertainment Weekly.

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Riley is best known for playing Elliot Carlin, one of Bob Newhart’s patients — a role he reprised in 1985 on the NBC medical series St. Elsewhere. He also appeared in several of Mel Brooks’ films, including History of the World: Part I, High Anxiety, and To Be or Not to Be.

Born in Cleveland, Ohio, Jack Riley got his start on NBC’s sitcom Occasional Wife, which ran from 1966 to 1967. In 1972, he joined The Bob Newhart Show. In the 1970s, he racked up a number of guest-starring roles on television; he played Gomez Adams in the TV movie The Addams Family Fun House and appeared on popular shows like The Mary Tyler Moore Show, M*A*S*H, and Diff’rent Strokes, where he played four different roles between 1978 and 1985.