It was on television that Young really made his mark, starring in Mr. Ed as Wilbur, owner of the titular talking horse. I adored Mr. Ed in my youth and I'm sure I watched every episode on Nick at Nite. I can't recall much of the show's plots though, outside of the one with Mae West.
Young's other great contribution to my childhood entertainment was his lenghty turn as the voice of Scoorge McDuck on television's DuckTales cartoons. Young's career in radio clearly trained him for animation work (like so many radio veterans) and with his adopted Scottish accent I doubt anyone recognized his voice (though if you know Young provided the voice it's apparent immediately).
Rest in peace Mr. Young.