Pronounced like "Cook" (as opposed to "Kotch", say) Koch is also known as one of the primary writers for radio performers Bob and Ray; and it was this aspect that brought him to Mad when scripts from the same show were reproduced in the magazine with caricatures of the star duo drawn by Mort Drucker.
However, Koch's most enduring contribution to Mad is almost certainly 43-Man Squamish, a fictitious field sport which ironically became popular in real life, due not only to Koch's ideas and scripting but also to illustrations provided by the late George Woodbridge.