Like most comic book based movies these days, "X-Men: Days Of Future Past" has a post-credits scene that tees up the next movie, teasing events and characters that will play into 2016's "X-Men: Apocalypse."

If you've never read the comic books the movie may be based on, you were probably left scratching your head harder than that Thanos reveal mid-credits in "The Avengers." And if you have read the comics? Well, chances are, you may still have been scratching your head.

So here's everything you need to know about the "Days of Future Past" post-credits scene, and why it's important for the future.

MASSIVE SPOILERS PAST THIS POINT.

Okay, brief recap of the scene for those of you who were left stupefied as you exited the theater. The camera reveals a man in a cloak standing on a sandy dune. Thousands of followers are chanting his name, bowing to him. Slowly, it's revealed that, with his hands raised, he's building the ancient pyramids with his mind. The camera zooms around to reveal a teenager whose skin is completely grey.

Huhbuhwha?

First of all, let's explain what those followers were chanting: they were saying the teenager's name, En Sabah Nur. In the comics, that's the human name of Apocalypse, a nearly 5,000-year-old mutant, the first one ever in recorded history.

As a kid, Nur learned through enslavement that the world was all about survival of the fittest. With his massive powers, he quickly grew to prominence and eventually was worshipped as a god by the Clan Akkaba -- regular humans and most likely the people bowing down to Nur in the post-credits scene.

Before we get to the next part, it's important to understand what Nur's powers are -- and that's basically all of them. Nur is strong, fast, invulnerable, can fly and teleport, is able to change his body's form at will, create force-fields and destructive blasts of energy, and can manipulate and move objects with his mind. Oh, and he's also immortal.

So knowing that, centuries later (because immortal) Nur has grown in power and prominence enough to name himself Apocalypse. He's also gotten some sweet battle armor and a massive sentient ship named Ship.

Most importantly, he's also taken on four "horsemen," the legendary forerunners of Apocalypse: Pestilence, Famine, War and Death. Occasionally they've been the literal personification of these entities. Also occasionally, they've been mutants, including the X-Men Wolverine and Angel.

So let's tie all this back to that scene! We know that director Bryan Singer has described the upcoming "X-Men: Apocalypse" as a disaster movie set in the 1980s. This is pure speculation, but with the end-credits tease being set at least 3000 years in the past (since that's when the Great Pyramids were built), Apocalypse has been around since long before and throughout the continuity of the "X-Men" movies.

It's entirely possible that given the changes in the timeline, specifically the Sentinels not rounding up mutants as they do in the original X-Men movie timeline, that Apocalypse is now free to make his move for global domination. The key thing to remember here is that Apocalypse isn't pro-mutant or pro-human, he's pro-survival. If he saw a world where humans and mutants were being wiped out, he wouldn't bother interfering, he'd leave.

With the Sentinels out of the way, the world is primed for Apocalypse to push his own twisted philosophy -- and if he can build the pyramids with his mind, there's nothing that can stop him.

And no, we have no idea who that actor was, either.

What did you think of the post-credits scene? And are you looking forward to "X-Men: Apocalypse?"