Ahead of Avengers: Doomsday, Robert Downey Jr.'s Doctor Doom has already matched the exact number of MCU appearances Thanos had before he took the spotlight in Avengers: Infinity War. Thanos' rise across the Infinity Saga was gradual, with him first appearing in a single post-credits shot at the end of 2012's The Avengers before a brief yet more substantial role in 2014's Guardians of the Galaxy and later, a more direct declaration of war against the heroes in the stinger of 2015's Avengers: Age of Ultron. Those three appearances over six years created a sense of looming inevitability without fully introducing the character. Thanos' real introduction, complete with backstory, arrived in Avengers: Infinity War, fleshing out the villain as he fulfills his mission of gathering the six Infinity Stones to save the universe in his own twisted way.
The Multiverse Saga, meanwhile, originally followed a similar long-game plan with Jonathan Majors' Kang the Conqueror. Variants were planted in Loki and given a major push in Ant-Man and the Wasp: Quantumania, with Avengers 5 even originally titled The Kang Dynasty. However, Majors' departure derailed those plans, prompting Marvel Studios to pivot to Robert Downey Jr.'s Doctor Doom as the new culminating threat of the retitled Avengers: Doomsday.
Even with that compressed timeline, Doom's overarching presence has now matched Thanos' milestone pre-Infinity War. Marvel Studios effectively utilized a plan to establish him across different corners of the Multiverse just in time for his proper introduction in Avengers: Doomsday.
Thanos' Three Pre-Infinity War Appearances
The Avengers - Post-Credits Scene (2012)
After Loki is defeated by the Avengers and the Tesseract secured, the Other reported to a mysterious figure on a distant throne. The camera revealed Thanos (initially played by Damion Poitier) smiling as he heard that Earth had proven "unruly" and "therefore cannot be ruled."
This brief, silent cameo completely reframed the entire film, confirming that the Chitauri invasion was never Loki's idea alone. Thanos' debut in The Avengers was significant because it was the first on-screen confirmation that a larger cosmic threat was already moving pieces behind the scenes, raising the stakes for the heroes ahead of the Infinity Saga's culmination.
Guardians of the Galaxy (2014)
Josh Brolin made his debut as Thanos in Guardians of the Galaxy, showcasing his proper appearance while negotiating with Ronan the Accuser about obtaining the Power Stone. He loaned Ronan Gamora and Nebula in exchange for the Orb.
While his brief appearance successfully announced his presence and confirmed his desire to collect the Infinity Stones, the Mad Titan at this juncture was still largely in the shadows. Still, his presence alone underscored how imposing he was and set the stage for his power to move pawns in the background to achieve his goal.
Avengers: Age of Ultron (2015)
Following Ultron's defeat and Vision being born with the Mind Stone as his conduit, Thanos appeared in the mid-credits scene of Avengers: Age of Ultron. The sequence showed the Mad Titan reaching into a vault and retrieving the Infinity Gauntlet, telling the audience, "Fine. I'll do it myself."
This moment in Age of Ultron served as the clearest signal yet that the Infinity Stones are his next target and that he is done working through pawns, indicating that he will actively seek them out himself.
Doctor Doom's Three Matching Appearances Heading to Avengers: Doomsday
The Fantastic Four: First Steps - Mid-Credits Scene (2025)
The Fantastic Four: First Steps' mid-credits scene officially revealed the first high-definition look at Robert Downey Jr.'s Doctor Doom.
Set years after the main story on Earth-828, Vanessa Kirby's Sue Storm left four-year-old Franklin Richards briefly in the Baxter Building, only to return to find a hooded Victor von Doom in green sitting with the boy, holding a metallic mask.
This scene not only featured Doom's MCU debut, but it also established his presence in the Fantastic Four's universe and his early interest in Franklin. This moment also effectively reorients the entire Multiverse Saga, marking it as the true starting point for unleashing his sinister plans across all of reality.
Avengers: Endgame Encore - Post-Credits Scene (2026)
One of the exciting Avengers: Endgame Encore's post-credits scenes featured the return of Mark Ruffalo's Bruce Banner.
Following his unexpected rampage at the Department of Damage Control Facility caused by Sadie Sink's Jean Grey's manipulation, the stinger confirmed that Banner isolated himself deep underground to find a solution to his lingering Hulk-out problem. However, his plan was derailed when Doctor Doom appeared and calmly informed Banner that he had arrived to collect him.
This sequence marks Doom's first clear action (and arrival) on Earth-616, kickstarting his pattern of gathering powered individuals from the Sacred Timeline. It also led to theories that Doom might have also recruited Tom Holland's Spider-Man into his team, raising the stakes ahead of Avengers: Doomsday.
VisionQuest - Finale Post-Credits Scene (2026)
Perhaps the most intriguing connection to Avengers: Doomsday happened during the much-talked-about mid-credits scene of VisionQuest. The sequence returned to the events of Doctor Strange in the Multiverse of Madness, continuing what happened after Elizabeth Olsen's Wanda Maximoff sacrificed herself on Mount Wundagore.
As it turned out, Doctor Doom arrived to lift debris from Wanda's body, declaring his intentions to use her power for his plans for the Multiverse, saying, "Scarlet Witch, awaken. Your power will be mine." Wanda's eyes open, glowing green, effectively resurrecting her and using her immense powers for his own benefit.
This sequence retconned Doom's presence further back in the timeline and confirmed he was actively assembling a major team ahead of Avengers: Doomsday.
