When I stumbled on the video of Walt Disney on What's My Line it was recommended that I watch a video of Donald Duck on the same program. This excerpt from December 12, 1954, honestly had me in stitches.
I honestly cannot think of any video where I have actually seen Clarence "Ducky" Nash at work. And I loved this, especially since the guests have such a hard time pinning down what Mr. Nash did for a living. And of course, you have to stay for the end to see him voicing his famous counterpart Donald Duck.