
Acting
Arthur Adolph "Harpo" Marx (November 23, 1888 – September 28, 1964) was an American comedian and film star. He was the second oldest of the Marx Brothers. His comic style was influenced by clown and pantomime traditions. He wore a curly reddish wig, and never spoke during performances (he blew a horn or whistled to communicate). Marx frequently used props such as a walking stick with a built-in bulb horn, and he played the harp in most of his films.
Description above from the Wikipedia article Harpo Marx, licensed under CC-BY-SA, full list of contributors on Wikipedia.

The Marx Brothers: Hollywood's Kings of Chaos
as Self (archive footage)

Dalí & Disney: A Date with Destino
as Self (archive footage)

Inside the Marx Brothers
as Self (archive footage)

The Our Gang Story
as Self (archive footage)

The Unknown Marx Brothers
as Self (archive footage)

The Ten-Year Lunch
as Himself (archive footage)

Classic Comedy Teams
as Self (archive footage)

Going Hollywood: The '30s
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Hollywood Out-takes and Rare Footage
as Self (archive footage) (uncredited)

Showbiz Goes to War
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The DuPont Show with June Allyson
as Benson · 1 ep.

DuPont Show of the Month
as Narrator · 1 ep.
America After Dark
as Self · 1 ep.

The Dinah Shore Chevy Show
as Self · 1 ep.

General Electric Theater
as Nick · 1 ep.

I Love Lucy
as Harpo Marx · 1 ep.

The Colgate Comedy Hour
as Self · 4 ep.

The Ed Sullivan Show
as Self · 1 ep.
Horse Feathers
1932