The upcoming 2016 movie, "X Men: Apocalypse", will consist of two mutant factions that will battle each other.

As reported by Cinema Blend, the first one will be Professor Charles Xavier-led X-Men, which will include the "First Class" allies and the new students of the Xavier Institute for Higher Learning. The other group will be led by Apocalypse and his Four Horsemen. However, there are other mutants as well who don't belong to either of these groups.

The newly-released trailer of "X Men Apocalypse" has an amazing Easter Egg with a reference to the notorious underground mutant group known as The Morlocks.

This group has been featured in various X-Men comic books for decades and it seems like they will be debuting in the next instalment of the X-Men film series.

In the initial moments of the trailer, a hooded Apocalypse enters a dark room where the silhouette of two people can be seen. One of them, with a Mohawk, is revealed to be Storm (Alexandra Shipp).

However, the other person seems to be a prominent Morlock member who is known by the name of Caliban.

In another instance, a lady, probably one of the teachers from the institute, is seen telling Xavier about secret societies that knew about the origin of Apocalypse.

It seems that she is referring to the Morlocks as they mostly live underground with hardly anybody knowing about them.

The first look of the trailer gives an impression that the movie is going to be about the war between X-Men and Apocalypse. However, there might be a possibility that X-Men will have to deal with the Morlocks too.

It is yet to be revealed whether they will be an ally to Xavier's students or will fight against them.

Besides that, there may be a slight chance that the story of "X Men: Apocalypse" will pave the way for the next Avengers movie.

Though there is no such official confirmation yet, given how the Marvel Cinematic Universe is expanding, there is a significant possibility of it.