The latest Battlefield 4 DLC, i.e. the one that comes with the map Dragon Valley, has a really ridiculous Easter egg in it. The Easter egg isn’t ridiculous in itself, it’s actually quite lame to be honest but the amount of work you’ve to do in order to get a hold of it is what’s ridiculous.
In the video below, YouTuber jackfrags does a walkthrough on how you can achieve the Easter egg. Not only does it take a lot of mathematical work, which we obviously don’t have the time for, but a portion of the easter egg is unique to every individual who plays the game. So you can’t just copy-paste the techniques you learn from this video into your game in hopes of getting the Easter egg yourself, instead you’ll have to do a portion of the steps from the video below and that involves learning and interpreting Morse code.
Good luck with that.