Answer:

HARPO

Answer	Crossword Clue
HARPO	Chico's brother
HARPO	Arthur Marx, familiarly
HARPO	Groucho's brother

HARPO	Winfrey's production company
HARPO	Chico's bro
HARPO	Mum Marx
HARPO	Madcap movie mute
HARPO	"... Speaks!" (1961 autobiography)
HARPO	Silent film star's nickname?
HARPO	Marx with a horn
HARPO	Silent screen star

HARPO	A Marx
HARPO	Silent film star
HARPO	Actor-public speaker who often began "Unaccustomed as I am to speaking ..."
HARPO	Noted horn honker
HARPO	Curly-haired pantomimist
HARPO	Silent film star?
HARPO	Funnyman with a horn
HARPO	Speechless fellow?

HARPO	Groucho's foil, often
HARPO	One of Groucho's bros
HARPO	One of Zeppo's brothers
HARPO	Mute Marx
HARPO	"Duck Soup" brother
HARPO	Horn-honking Marx
HARPO	The silent Marx
HARPO	Mute Marx brother

HARPO	Curly-haired Marx brother
HARPO	Oprah's company
HARPO	Silent movie star?
HARPO	Horn-honking Marx brother
HARPO	Julius : Groucho :: Arthur : ...
HARPO	Honking film brother
HARPO	Marx Brother with a horn
HARPO	Oprah Winfrey's company

HARPO	Character who communicated with a horn
HARPO	Famed mime of old films
HARPO	Ms. Winfrey's production company
HARPO	One of Groucho's brothers
HARPO	Silent film comic