Imagine that you're hiding an Easter egg in your game. Perhaps it's some text or an image that pops up after doing some obscure set of tasks. Whatever the case, you want this Easter egg to remain hidden for a long time. Now, you're worried that someone will discover it by going through the game's resources or even by using tools to search through and modify the game's values in the memory (or by going through the compiled program file). What kind of countermeasures would you employ in your code to ensure (as much as possible) your Easter egg would not be found by illegitimate means?

Make the easter egg data be assembled from pieces of real data legitimately used elsewhere in the game.

And here I was thinking you were talking about actual easter eggs, since Easter was yesterday.

None. Easter eggs just aren't important enough in the development process for me to spend extra time and effort trying to hide them.

Well, this is only a semi-serious question meant to be purely theoretical without taking practicalities into account. I'm just interested in hearing what schemes people can think up to hide an Easter Egg in the code.