I remember being convinced that the little Muppet was the Jedi Master because i was familiar with fairy tales. Luke was being tested. It was far too obvious. Lucas is many things but subtle isn’t one of them. But still it was clever and Frank Oz did it so masterfully you almost believe he is a real living breathing being. Mark Hamill is a good part of that as well though, because if he didn’t sell it in his performance it would have fallen all apart. With one of the very best scores every written for film, and one of Williams finest achievements.