Graduated from Yale and first performed comedy routines in nightclubs before making his bow on stage in the late 1920's. Broadway debut followed in 1930 with the play "Overture", under his original name John Hoysradt. Was a member of the Mercury Theater from 1937 until called up for military service in 1945. Thin-lipped and silver-haired hard-case or villain of many a 1960's or 70's TV episode.
He had several guest appearances on the 1960s TV comedy show "Hogan's Heroes" (1965). He mostly played a high-ranking German Officer in the show, but never the same role twice.
He was the television spokesman in a series of Midas Muffler commercials in the 1960's.
In 1937 he performed (as John Hoysradt) at the prestigious Rainbow Room at Rockefeller Center. He headlined as 'the Master of Satire.'
In his early years of performing, he put together a nightclub act doing impressions of famous celebrities. His impersonation of Noel Coward was so good that he was hired for the original Broadway comedy "The Man Who Came to Dinner" in 1939, in which he played Beverley Carlton, a role obviously based on Coward himself.
One of a long list of actors and crew who worked on the film The Conqueror (1956) in 1956 that died from cancer some years later, including John Wayne, Susan Hayward, Agnes Moorehead, and Pedro Armendáriz, who was the first to contract cancer and committed suicide rather than face the horror of it.
One of the very few actors to have appeared in both the original Star Trek series and the original Battlestar Galactica.