Family of the Director
In the 1981 movie "Excalibur", director John Boorman's three children appeared. His son Charlie played the young Mordred. His daughter Katrina played Ygraine, Arthur's mother, in the beginning of the movie. The real egg is the identity of the actress who portrayed The Lady of the Lake. She was never mentioned in the credits and no one seemed to be able to identify her, but it was finally revealed that it was Boorman's other daughter, Telsehe.