He may be best remembered from The Palm Beach Story (1942) as Toto, the nonsense-talking, mustachioed man who hopelessly pursues Mary Astor's Princess Centimillia.

Before beginning to make films in 1920, he was well-known in Germany as a stage comedian.

Pabst's Pandora's Box with Louise Brooks – playing primarily comic roles, then he left Germany in 1933 due to the rise of Adolf Hitler.

[1] Arno appeared three times on Broadway,[3] notably in the musical Song of Norway and the play Time Remembered by Jean Anouilh,[4] for which he was nominated for a Tony Award as Best Featured Actor in a Play in 1958.

[1] He was married four times: He died from Parkinson's disease in Woodland Hills, California on August 17, 1975, aged 79.