
The Fantastic Four: First Steps not only introduced Marvel’s First Family into the MCU but expanded its lineup of villains. While no doubt Galactus was the Phase 6 film's main threat, the Multiversal movie also confirmed the existence of a surprising number of other comic book baddies.
When The Fantastic Four: First Steps arrived in theaters, fans knew to expect Galactus and the Silver Surfer. But, surprisingly, director Matt Shakman's reboot did far more than that. Through a villain-packed opening montage, references and appearances, and the film's credits scenes, First Steps established a whole rogue's gallery of classic comic book villains within the Multiversal Earth-828, which is now officially part of the MCU.
Released in theaters on July 25, The Fantastic Four: First Steps stars Pedro Pascal as Reed Richards, Vanessa Kirby as Sue Storm, Joseph Quinn as Johnny Storm, and Ebon Moss-Bachrach as Ben Grimm/The Thing. As part of the Multiverse Saga, Marvel Studios' reboot of the Fantastic Four takes place in an alternate, 1960s-inspired retro-futurist world threatened by the planet-eating Galactus.
10 Fantastic Four Villains Marvel Just Brought Into the MCU
Galactus

The film's central villain, Galactus, played by Ralph Ineson, is an ancient cosmic being who feeds on planets to satisfy his never-ending hunger (check out Galactus' MCU backstory here). Adding to the threat of him consuming Earth-828, Galactus is also looking for his replacement and sees Franklin Richards, the son of Reed and Sue, as the perfect candidate. Since Galactus wasn't destroyed but rather transported somewhere else, it's possible that he could return to the MCU.
Silver Surfer

Heralding Galactus' arrival and adding to the Fantastic Four's problems is Shalla-Bal or Silver Surfer, played by Julia Garner. First Steps reveals the metallic-skinned Silver Surfer agreed to become Galactus' herald in exchange for him sparing her planet, a past Johnny Storm reminds her of after learning her language.
Giganto

Appearing in The Fantastic Four: First Steps' opening montage (following being spotted in a First Steps ad), Giganto made his comic book debut in The Fantastic Four #1. In what appears to be a tribute to that comic book, Matt Shakman recreated the cover and its green monster in live-action. Giganto is portrayed as one of the threats the Fantastic Four faced during their successful four-year superhero career leading up to the arrival of Galactus.
Mole Man

Besides Galactus and Silver Surfer, Mole Man was the Fantastic Four villain with the most screen time in First Steps. Confirmed in Marvel Comics' official The Fantastic Four: First Steps prequel comic, Paul Walter Hauser's Mole Man and Giganto are defeated early on in the film, but he later helps the team (mainly because of Sue Storm) by sheltering the citizens of Earth-828's New York City underground in Subterranea. He also briefly appears in the film's animated post-credits sequence.
Red Ghost & His Super Apes

While John Malkovich's Red Ghost was ultimately cut from the film, one of the Fantastic Four comic book villains' Super Apes makes an appearance in First Steps' action-packed opening montage. Furthermore, Red Ghost and his Super Apes appear in animated form during The Fantastic Four: First Steps' post-credits scene, which is the title sequence to the in-universe Fantastic Four cartoon.
The Mad Thinker

The Mad Thinker is never shown in The Fantastic Four: First Steps, but the highly intelligent antagonist is referenced early in the film for having tried but failed to destroy New York City.
Diablo

This potion-powered comic book foe gets a shout-out in The Fantastic Four: First Steps when Reed Richards attempts to "baby-proof" New York by taking down multiple criminal organizations, one of which is headed by Diablo. While he never appears in live-action, he does show up via animation in the movie's post-credits scene.
The Wizard

Another crime lord that Reed Richards takes off the board ahead of becoming a father is The Wizard, an enemy who uses his intelligence for evil and is known for passing off his scientific experiments as magical tricks.
The Puppet Master

The third and final crime lord Reed Richards takes down is the Puppet Master, or Phillip Masters, the father of Ben Grimm's comic book love interest, Alicia. He's known for using radioactive clay to create duplicates of individuals and then controlling their minds and actions.
Doctor Doom

Following a nod to the villain's homeland of Latveria, Victor Von Doom is finally revealed during The Fantastic Four: First Steps' post-credits scene, but only from behind, where he's removed his mask and interacts with young Franklin Richards (find out why Doom wants Franklin here). Of course, this tease alludes to what awaits in Avengers: Doomsday as Robert Downey Jr. is confirmed to be playing Doctor Doom and facing off against not only the Fantastic Four but also Fox's X-Men and Earth-626's Avengers, New Avengers, and the Wakandans.
It's also possible that Doom's appearance in The Fantastic Four: First Steps is his second post-credits appearance, as fans speculated he's the one aboard the Fantastic Four's ship in the Thunderbolts* post-credits scene directed by the Russo Brothers.