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Attended USC Film School in 1984. He provided the final designs for "Star Wars" characters Yoda and Boba Fett. Answered an ad while a student at Cal State-Long Beach, which was looking for employees. That ad was for George Lucas whom Johnston became acquainted with. He was employed a storyboard artist who would watch Lucas do his editing. Eventually, Johnston decided to leave Lucas' company and travel with the money he had saved up. But Lucas suggested that he go to USC film school (his alma mater), which Lucas would get him to the front of the line for applicants, pay for his tuition, and keep Johnston as a part time employee with his salary. Johnston said he would have been crazy not to accept the offer and immediately said yes.