Frank Oz is the voice actor who plays Yoda, both in The Force Awakens and the rest of the Star Wars films. But he also plays Fozzie Bear, Miss Piggy, Animal, and Sam Eagle, in addition to previous roles as Cookie Monster, Bert, and Grover.
Has Frank Oz commented on the similarities between Yoda and any of his other characters?
There are significant similarities in voice inflections between some of these characters. This would be expected from the same actor. But has he commented on personality similarities?
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ONGOING RESEARCH
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I am interested in this, but I don't have an answer, so I will post things if I find them.
In this interview, Frank Oz says that the thing he likes most about Yoda is that, if there was only one piece of candy left on a plate, Yoda would demand the piece of candy for himself and practically steal it. Frank Oz said this character trait balanced out the Zen Master aspects of Yoda. So maybe Miss Piggy, Cookie Monster and Animal may be part of Yoda. The relevant section starts around 17:45 into the video.
In addition to Frank Oz's comment, the article at this link discusses George Lucas' intention that Yoda be a blend of Miss Piggy and Kermit The Frog. In fact, the article contains an embedded video of George Lucas himself saying that Yoda should look and feel like the child of Kermit and Piggy. @RogueJedi said this in a comment below. Here is a photo of Luke Skywalker with yoda and yoda's hypothetical parents: