Batman v Superman: Dawn of Justice is fast approaching, and each new clip or still from the film only continues to fuel the fires of fan speculation.

After months of rumors, the latest trailer revealed that Doomsday will face off against Batman, Superman and Wonder Woman in the movie. However, is Doomsday the real threat, or is there an even bigger villain lurking in the shadows?

That's what fans have been asking ever since the first trailer for the film arrived. That trailer and subsequent ones show an extremely out-of-place scene that involves Batman wearing a trench coat and goggles in a desert environment, battling what appear to be soldiers loyal to Superman as well as what look like flying bat-/bug-like creatures.

The flying creatures look awfully similar to Parademons, loyal minions to the DC Comics big-bad Darkseid. That has led many to believe that the character will make an appearance of some kind in the film. If you're not familiar with Darkseid, he has long been one of the most dangerous characters in the DC universe.

Darkseid rules his planet of Apokolips with an iron fist and has plans to conquer the entire galaxy by erasing free will. He is, for all purposes, the personification of tyranny, modeled after Adolf Hitler himself and inspires to-the-death loyalty from his followers.

He is very comparable to Thanos from the Marvel Universe, and it would certainly make sense for DC to set up its own galactic threat. If you remember, Thanos was teased at the end of the first Avengers film, shown to be behind the scenes manipulating events. Now, Marvel is building toward all-out-war with the character in the two-part Avengers: Infinity War. If Batman v Superman does introduce Darkseid, it would likely be in a similar fashion, briefly teasing the villain who will then become the main threat in the two-part Justice League film.

A new piece of evidence seems to support the Darkseid theory. A recently-released still image from the latest issue of Empire magazine shows the desert scene from Batman v Superman as Batman stares out at a massive "Omega" symbol in the sand. The Omega symbol is that used by none other than Darkseid, seeming to confirm that the flying creatures are, in fact, Parademons.

However, that still doesn't explain what is going on. Why does Superman have an army of soldiers? Where did the demons come from? Where is Wonder Woman?

Nobody is quite sure, and so far, director Zack Snyder isn't giving any clues. However, a costume designer for the film had this to say about the sequence:

"Zack [Snyder] had a great idea of this sort of nightmare-ish vision, almost a vision of the future, a post-apocalyptic vision. It's like a dream that Ben [Affleck] has, so we wanted to, it has almost a Mad Max quality to it where it's like the end of the world, trying to survive."

It certainly does seems to be a post-apocalyptic vision of some kind. If this is indeed Batman's nightmare, it seems unlikely he would simply "make up" the Parademons and Omega symbol. It stands to reason then that perhaps Batman (somehow) knows about the ever-looming threat of Darkseid. His greatest fear could be that Superman and Darkseid, two aliens, might unite to conquer Earth, and that he would ultimately be powerless to stop it. It's possible Batman's vision is of Darkseid trying to transform Earth to his liking, as the images have an uncanny similarity to how Apokolips is often depicted, with what appears to be a volcano and the ruins of a city (perhaps Gotham or Metropolis) in the background.

Post-apocalyptic visions aren't unheard of in the DC universe thus far. Man of Steel had one too, where Zod gives Superman an apocalyptic vision of the future where Krypton is reborn on Earth at the expense of the human race. In the dream, Superman drowns in a sea of human skulls.

In the New 52 Justice League comics, Darkseid is actually the first villain the heroes face as a team. The first issue finds the various Justice League members uniting to battle an invading army of Parademons, with Cyborg later receiving a vision of Darkseid before the character officially appears in following issues.

Given all of the above, it seems very likely that Batman's nightmare isn't just a normal bad dream. For Batman to simply "dream" the Omega symbol and Parademons doesn't make sense. Whether it's a vision of the future, an alternate reality or something else isn't yet known, but rest assured that there is certainly more going on in Batman v Superman than two of DC's biggest heroes fighting.