[Watch our video discussion & analysis of X-Men: Days of Future Past characters here!]

A decade ago, when moviegoers were jumping back and forth between X-Men, Spider-Man and Fantastic Four films - before Marvel Studios even existed as a self-financed production house - Marvel Comics fans were eagerly awaiting the chance to see the towering Sentinel robots from the X-Men books appear on screen. These lethal, mechanical beasts are a nightmare for mutantkind, designed with the sole purpose of tracking, capturing and/or killing mutants globally - they are the frightening symbol of anti-mutant hysteria.

Since anti-mutant sentiment has been a running theme through the entirety of the X-Men film franchise, it's shocking that it's taken seven movies to finally see them in action on screen - not counting the Danger Room cameo of a Sentinel's busted head appearing in the intro of X-Men: The Last Stand. The X-Men were training to battle Sentinels in this summer we're finally going to see that training pay off.

When X-Men: Days of Future Past made a buzzworthy appearance at Comic-Con last summer, with Twentieth Century Fox and director Bryan Singer bringing the film's entire cast onstage together, they teased the big show with clever viral marketing with a display honoring Bolivar Trask (creator of the Sentinels) along with some fake protesters. Whether you're pro-mutant or anti-mutant, it was hard to avoid the Sentinel head on display. It was the head of the first Sentinel units put into the field, beginning in 1973 - Mark I units that stand two to three times taller than an average person. These units even served on President Richard Nixon's protective detail.

In the 40 years since, many advancements have been made by their creators at Trask Industries and in the near future the massive Mark Xs have scoured the planet, hunting the last surviving mutants. It's been a long wait, but the Mark X design has finally been revealed as part of Empire Magazine's exclusive set of 25 X-Men: Days of Future Past character covers.

X-Men Days of Future Past Empire Cover 25 Future Sentinel

It's very alien in nature, almost organic-like in its design - as if it can change shape and size. Could it be leading to a possible introduction of Nimrod, the more advanced futuristic Sentinel created by Sentinels? Is this one of many or one-of-a-kind?

What are your thoughts on Singer's take on the iconic Sentinel design and how does it compare to the Sentinels frequently seen in the comics and cartoons?

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More: Why Does Wolverine Time-Travel?

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Bryan Singer directs X-Men: Days of Future Past with newcomers Peter Dinklage, Omar Sy, Boo Boo Stewart, Fan Bingbing, Evan Peters, Adan Canto, Josh Helman, Evan Jonigkeit along with returning stars Jennifer Lawrence, Michael Fassbender, James McAvoy, Nicholas Hoult, Patrick Stewart, Ian McKellen, Hugh Jackman, Anna Paquin, Ellen Page, Shawn Ashmore, Halle Berry, Lucas Till, and Daniel Cudmore.

X-Men: Days of Future Past hits theaters May 23, 2014. Fantastic Four opens June 19, 2015X-Men: Apocalypse releases May 27, 2016 release.

Follow Rob on Twitter @rob_keyes for your Marvel movie & TV news!