5 MCU Villains That Should Cameo in Marvel’s Thunderbolts

In May 2025, the baddies and anti-heroes of the Marvel Cinematic Universe will finally get to step into the spotlight with Thunderbolts*. A bevy of morally-gray figures like Yelena Belova (Florence Pugh), Bucky Barnes/The Winter Solider (Sebastian Stan), and John Walker/U.S. Agent (Wyatt Russell), will team up to form a team known as the Thunderbolts. What will happen in this solo movie (and the significance of that pesky asterisk) is still shrouded in mystery. However, Thunderbolts* will clearly give audiences a chance to better understand some of the murkier figures populating a world of Spider-Man’s and Captain America’s.

Given that this is a Marvel Cinematic Universe project, there’s no chance the Thunderbolts* cast list reveals all of the superpowered figures and familiar faces that will appear in this movie’s runtime. This project will inevitably feature other baddies from past Marvel Cinematic Universe productions, which could lead to some mighty enticing cameos.

Five MCU foes from the past seem like they’d be perfect fits for Thunderbolts. Who knows if they’ll even get name-dropped, let alone physically appear, – but it’s fun to imagine them rubbing shoulders with the likes of Yelena.

Justin Hammer

In his final minutes of Iron Man 2 screentime, the nefarious tech whiz Justin Hammer (Sam Rockwell) proclaims that the film’s lead characters haven’t seen the last of him. He may be down, but he’s certainly not out. Despite the conviction in his voice, Hammer hasn’t lived up to this word. Save for an uncomfortable cameo in the short film All Hail the King or showing up in one What If…? episode, Hammer’s been entirely absent from the Marvel Cinematic Universe.

All these years later, a movie about Marvel villains could be an optimal time to see Hammer again, especially the Thunderbolts* need weapons for a specific mission. Plus, it’d be amusing to see such a grounded non-superpower guy deal with these heightened baddies.

Baron Helmut Zemo

Baron Helmut Zemo already returned to the Marvel Cinematic Universe after his Captain America: Civil War debut with a lengthy guest stint on The Falcon and the Winter Soldier. Thunderbolts* could be fertile ground for another Zemo appearance, especially since he really is the cream of the crop among MCU villains. After all, he broke up The Avengers and he didn’t need a super-suit or special serum to do it! Now that Zemo’s officially a recurring MCU fixture, he really needs to return for Thunderbolts*.

[Related: 10 Years Ago, Marvel Teased A Very Different Kind of Ant-Man Movie (Watch)]

Mac Gargan/The Scorpion

No Marvel hero has quite the iconic gallery of villains as Spider-Man. It’d be a shame to do a movie about Marvel adversaries like Thunderbolts* without featuring one of this web-crawler’s foes. One exciting candidate for such a cameo would be Mac Gargan/The Scorpion, who appeared as a normal criminal in Spider-Man: Homecoming explicitly teasing that he’s hankering for some revenge against Spider-Man. Putting him in the Scorpion outfit even for one Thunderbolts* action sequence could provide some enthralling entertainment. Plus, it’s always been awkward that this Scorpion tease has never been properly fulfilled in the Marvel Cinematic Universe.

Emil Blonsky/The Abomination

Across She-Hulk: Attorney at Law and Shang Chi and the Legend of the Ten Rings, it’s clear The Incredible Hulk villain Emil Blonsky/The Abomination has reformed quite a bit thanks to an unexpected friendship with sorcerer Wong. However, who’s to say this monstrous fellow can’t relapse back into his nefarious ways, even if it’s just for one Marvel Studios movie? Thunderbolts* would be a sublime place to see The Abomination back in malicious mode. Plus, it’d be thrilling to see one of the earliest Marvel Cinematic Universe villains return for Phase Five’s swan song.

Trevor Slattery

True, Trevor Slattery was never a Thanos/Ultron/Loki-level threat to any Marvel heroes. However, he still collaborated with Aldrich Killian for deeply personal means and (however unintentionally) used the deaths of innocents to give himself a steady acting gig. Slattery was certainly connected to evil in his Iron Man 3 screentime before Shang-Chi and the Legend of the Ten Rings showed a lighter, more courageous side to the man. Having him reappear in Thunderbolts* could provide a symbol of hope to the members of this titular team secretly hoping for redemption. Slattery shows it is possible to be more than just your past villainous deeds. Also, his potential Thunderbolts* screentime would let Ben Kingsley once again steal scenes with his delightful Slattery performance – and provide a nice MCU connection to his upcoming role in the Wonder Man Disney+ series.

Thunderbolts* arrives in movie theaters everywhere on May 2, 2025