Yoda Was a Monkey in a Mask

Yoda-MeditatingSOURCE

When George Lucas was first contributing on the script for Empire Strikes Back, he didn’t initially plan to use a puppet for Yoda. His idea was to hire a monkey and stick it in a mask to play the now famous old Jedi master. But the idea was scrapped when Lucas decided that it would be harder to train a monkey than it would be to hire Frank Oz to puppeteer Yoda.