Angry Birds: The lost episode, can only be unlocked on Android. It is not an update, it is a episode where you must complete all four games 100% completed. All levels must have three stars, and Mighty Eagle feather. (Execpt Year of the Dragon.) Even all Space Eagle feathers. All episodes in Angry Birds Space (execpt Danger Zone) must have 3 stars!
So if you do that, you unlock the lost episode!
Big Brother Bird
The Pigs do their final try in stealing the eggs. They do all the things they did before, go underground, cardboard cutouts, ext. Ice Bird comes down to help.