Primarily a stage actor; for almost twenty years he appeared in "The Drunkard," (the old morality play that promoted temperance that W. C. Fields put on in "The Old -Fashioned Way" [1931]) that played at the Theater Mart in Los Angeles, under the direction of Galt Bell. After he retired, Karl Thomas and his wife Ada, also an actress, moved north to Port Hueneme, where they appeared in various professional and amateur productions on "the citrus circuit." In 1985, he appeared with local actress Helen Thomas in a production of "The Gin Game" in Ventura.