Marvel Studios packed its big presentation with even more multiversal chaos at SDCC this weekend, adding a Ryan Gosling Ghost Rider solo movie to its upcoming slate and bringing the cast of Avengers: Doomsday to the stage, even taking a little time out to reject Ryan Reynolds’ impassioned pleas to join the line-up as Deadpool.

One of the biggest reveals in the new Doomsday footage shown in Hall H was the arrival of the Sentinels. These towering mutant-hunting robots appeared as part of Doctor Doom’s attack, with the latest footage showing Robert Downey Jr.’s villain commanding an army of the iconic machines as they get ready to battle Thor and some of our other MCU heroes. In the action-packed sequence, Doom puts his hand to the ground, and the terrifying Sentinels rise against his foes.

For X-Men fans, this is a major reveal. The Sentinels aren’t just giant robots; they symbolize humanity’s fear of mutants and the prejudice at the heart of many big X-Men stories. They previously terrorized the screen during Fox’s X-Men: Days of Future Past back in 2014, but Doomsday marks their official arrival in the Marvel Cinematic Universe.

Some of the original Fox X-Men were confirmed to be part of the upcoming movie’s sprawling cast a while ago and were revealed as part of Marvel’s previous teasers. James Marsden (Cyclops), Rebeca Romijn (Mystique), and Kelsey Grammer (Beast) were also at SDCC to tease their X-Men roles in Doomsday.