Spoilers ahead. When it comes to X-Men villains, there are a handful that are considered iconic. There's Magneto of course, Wolverine's archnenemy Sabretooth, powerful Apocalypse, the robotic Sentinels, spooky Mr. Sinister, and sly Mystique (though now most think of her as a hero thanks to Jennifer Lawrence's portrayal). Another top tier X-Men bad guy is Juggernaut, who makes a surprise cameo appearance in Deadpool 2. And although it's a fun cameo, the actor who plays Juggernaut in Deadpool 2 is a mystery.
Bustle reached out to the studio for clarification on who is behind the mask in the film, but at the time of writing had not heard back. In Deadpool 2, Juggernaut appears as a hulking, helmet-wearing CGI creation who even gets his own cheeky theme song. It's not clear who's playing him, and the film's credits simply list Juggernaut as being played by "Himself." But even though there's mystery surrounding him, fans will be happy to hear that the character's enormous size much more closely resembles the classic comic book character than his previous on screen incarnation did. You see, Juggernaut's film debut came in 2006's X-Men: The Last Stand, a movie that infamously tried to cram in as many characters as possible with little regard for comic book accuracy. That version of Juggernaut was human-sized, portrayed by English actor Vinnie Jones, but his small stature wasn't the only aspect of the character that wasn't comics-accurate.
In X-Men: The Last Stand, Juggernaut speaks with a thick English accent. In the comics, he's American. In that film, he's a mutant, whereas in the comics, his powers are magical in origin. Finally, X-Men: The Last Stand does not acknowledge that the character has any connection to Professor X, when they are stepbrothers in the comics. Deadpool 2 at least hints at this point in the film, with Juggernaut stating that he wears his helmet to keep his brother out of his head — the implication being that his brother is Charles Xavier. This appearance, however, while undoubtedly an improvement over his previous film role, will probably still leave fans of the comic book character longing for more. So what's so special about he comic book version of the Juggernaut?
Simply put, the Juggernaut is one of the X-Men's oldest and most consistent enemies. The character first appeared in the twelfth issue of X-Men, back in 1965. His main power is that he is an unstoppable force — hence his name — and he wreaked havoc on the X-Mansion in his debut. It was soon revealed that his real name was Cain Marko, and that he was Professor X's stepbrother. The entire reason he was targeting the X-Men was so he could get revenge on Xavier after a lifetime of being jealous of the X-Men leader.
Juggernaut gets his powers from the crimson gem of Cyttorak, an artifact belonging to a mystical entity named Cyttorak (Marvel Comics clearly has a thing for high-powered magical gems). The gem allows him to be a vessel for the entity, granting him enormous size and imperviousness along with nearly limitless strength. These powers make him one of the X-Men's most formidable opponents, and he has defeated the entire team by himself on numerous occasions. He's also tussled with other Marvel heroes over the years — including Doctor Strange, Spider-Man, Thor, and yes, Deadpool — as he has consistently appeared in the comics ever since his Silver Age debut.
Juggernaut receives a more faithful treatment in Deadpool 2 than in X-Men: The Last Stand, even if the actor who brought him to life remains unknown. But it still pales in importance to the Juggernaut of the comics who has tormented the X-Men across six decades.