Actor in film and TV -- via the New York Times. After decades as a "serious" actor in films such as "Forbidden Planet," "Tammy and the Bachelor" and, perhaps the nadir of his career, "Day of the Animals," he went against type as the poker-faced idiot doctor on board "Airplane!" This led to a string of vastly more successful and more enjoyable comic performances -- he became one of the best comic actors of his time. His genuine skills, combined with his ability to mock his deadpan seriousness, were priceless.
Here's a masterly analysis of his appeal by A.O. Scott in the New York Times --
And here's a lovely tribute from his friend and co-worker, Robert J. Elisberg --