20 Things You Didn't Know About Star Wars: Revenge Of The Sith
8. George Lucas Provided General Grievous' Cough
George Lucas generally likes to keep out of the camera's way, and though he does make a fleeting live-action cameo in Revenge of the Sith as a blue-skinned politician at the Coruscant opera house, his more interesting cameo is one you'll have to keep an ear out for.
After developing a nasty cough during production, Lucas decided to record it and use it for General Grievous, who of course has a notable asthmatic cough throughout his appearance.
Even those highly familiar with Lucas' voice would struggle to catch this one, but there it is.