First things first… if you haven't seen X-Men: Days of Future Past yet you might not want to read any further. This article contains end-credits scene SPOILERS. If you did see the movie, and you want to know what it meant, then by all means… read on.
FOX announced earlier this year that the next X-Men movie will be X-Men: Apocalypse, so it's no surprise that Days of Future Past would set that up for us and tease the villain. Apocalypse is a very powerful and dangerous enemy who has caused a lot of problems for the X-Men and X-Factor teams over the years. The scene shown at the end of the credits is set in Ancient Egypt, and we get to witness Apocalypse building the Great Pyramids with his powers. In a recent interview with CinemaBlend, screenwriter Simon Kinberg explains why they chose to go with that scene:
"What you see is Apocalypse sort of using his powers to manipulate the Pyramids. And in the shot, you can see The Four Horseman sort of in shadow, or silhouette. Now, when we make the movie, it will not take place in ancient times. We went back and forth a lot on… what that scene should be. Bryan and I just locked into this idea of seeing Apocalypse at the height of his power and glory, which is what we imagined would have been in Egyptian times. It was just to give a tease of, ‘This guy is super-powerful, and there was a moment in time when he was essentially treated as a god, and he’s going to rise again in X-Men: Apocalypse.’"
He goes on to explain that the actor playing Apocalypse in the scene is young, but confirmed that the actor they used will NOT be playing Apocalypse in the 2016 sequel, and that this sequence was done just to show "that this force has been around for such a long time."
It was a really cool end-credits sequence and a great way to set up the presence and power of Apocalypse for the next X-Men chapter.
*Correction: A previous version of this post had pictures of Darkseid rather than Apocalypse. That's embarassing...