Okay, so you're probably wondering why we're talking about Halo 3 almost seven years after it originally released. That's natural, it's essentially a lifetime in the world of tech and video games. Well, here's the deal: Halo 3's developers at Bungie were super-keen on tucking all manner of secrets away within the game and apparently the final one has only just been found. As Beyond Entertainment tells it, a few members of the Halo YouTube community have been following the breadcrumb trail of clues that Bungie's been leaving for the past few years, and this Easter egg is a bit more personal than monkey people hidden in the game's opening jungle level. In fact, it's a birthday message for former senior-engineer Adrien Perez's wife.The catch is that this only appears on December 25th (or on a console with the system clock set to Christmas Day), and only after clicking in both analog sticks on the Xbox 360's controller during a level-loading screen. Let's be realistic, though, you probably traded the game in for pre-order credit at GameStop a long time ago -- maybe even for that Halo 4-themed Xbox 360. In that case, we've embedded video of the action just below.