We’ve had three official teaser trailers for Avengers: Doomsday so far, and it probably goes without saying that the 3rd release featuring the X-Men is the most exciting one so far. But while everyone focused on the lead characters (like Patrick Stewart’s Professor X, Ian McKellen’s Magneto, and James Marsden’s Cyclops), the background hides one of the X-Men‘s biggest enemies: the Sentinels.
Freeze the frame towards the end, and you’ll see the legs and feet of a giant Sentinel stopping into frame right at the end of the Avengers: Doomsday teaser trailer. As James Marsden’s Cyclops fires his optic blast into the sky, it moves behind him. It’s metallic and heavy. And yes, we’ve seen those boots before. Those are definitely Sentinels (who first appeared in 1965’s X-Men #14).
Sure, it’s a quick blink-and-you-miss-it moment, but the giant feet reveal that the X-Men won’t only be going up against Robert Downey Jr’s Doctor Doom in the upcoming film, but they’ll have to deal with their old enemies too.

These mutant-hunting machines don’t need an introduction. They’ve been around in the comics, and they were a major threat in the X-Men: The Animated Series. For those who don’t know, the 20-30 feet tall Sentinels were introduced as the creation of a scientist named Bolivar Trask. Their primary focus is to stop and destroy all mutants.
Now, that we’ve seen them, and it’s official, fans are throwing out all sorts of theories about their involvement in the film. Could there be a major fight at the X-Mansion where Doctor Doom hacks the machines in order to fight the X-Men? It sure looks like it.
Early rumors also pointed to a clash between the X-Men and Earth-616 Avengers, with Doom nudging everyone towards a huge battle. So, Cyclops basically has to deal with Avengers, Doom and now, the Sentinels too.







