Cameo
The creator himself, George Lucas made a cameo in Revenge of the Sith, if you watch the movie again closely, you may be able to catch him. It is not uncommon for directors to be in their own movies, either as small parts, extras or even as main characters. It really is up to them to decide, after all, they are the boss on set.
George decided that he wanted to be a blue alien and was dressed up as one for a very small clip. When Anakin enters the opera house to meet with Palpatine, you can see George Lucas for a few moments in a black gown and with blue skin. It was a great makeup job we must admit.