Marvel's What If…? episode 3 supports the fan theory that states that Ant-Man could have killed Thanos in Avengers: Endgame by entering his body and blowing him up from the inside. There are only very few ways to defeat a character as powerful as Thanos, as even the most powerful Iron Man armors are barely able to contain him. None of the Avengers or the Guardians of the Galaxy could stop Thanos in Avengers: Infinity War, and finally taking down the Mad Titan cost them the lives of Loki, Vision, Black Widow, and Tony Stark before they could finally stop him with the aid of time travel in Avengers: Endgame.

Before Avengers: Endgame was released, one particularly creative fan theory presented a much simpler solution than the Avengers' time travel. Drawing upon Ant-Man's return after his absence in Avengers: Infinity War, fans proposed the idea that Scott Lang would shrink, enter one of Thanos's orifices — his backside, to be more specific — and then enlarge himself once inside in order to obliterate the Mad Titan's body. Although the physics involved in this plan were mostly in favor of the theory, such an embarrassing defeat would have been unacceptable for the Infinity Saga's biggest villain.

Related: Phase 4: Could Hawkeye's Arrows Really Kill Thor? 

Thanks to What If…?'s playful handling of alternate realities and unique scenarios, this fan theory didn't go to waste. In episode 3, all candidates for Nick Fury's Avengers Initiative start dying one by one. After Tony Stark, Thor, and Hawkeye die under mysterious circumstances, Hulk's body grows disproportionately until he explodes. Then, it's revealed that Hank Pym has been using his Pym Particles to take down the Avengers and escape unnoticed. Like the Avengers: Endgame theory suggested, Pym enters Hulk's body, only this time he does it through a bullet hole. He throws a Pym Particle Disk onto the Hulk's heart and enlarges it until his entire body bursts in a green puff.

Thanos in Avengers Infinity War and Hulk in What If

The logic of several narrative elements in What If...? can be put into question. Episode 1 featured Red Skull opening a multiversal portal with the Tesseract without Captain Carter's intervention. Episode 2 presented a much weaker version of Thanos who somehow abandoned his quest to collect the Infinity Stones with the help of T'Challa's charm. In the same unlikely vein, whether Hank Pym, Scott Lang, or the MCU's Wasp, Hope van Dyne, could kill Hulk with only Pym Particles in the MCU's main timeline is difficult to imagine.

Like the comics on which the Disney+ series is based, What If...? focuses on hypothetical scenarios where the sheer improbability of the situation is the source of its fun. At least in the main MCU timeline, it's highly unlikely that all the Avengers, let alone Hulk, would have let Hank Pym defeat them so quickly. And as compelling as the "Thanus Theory" was, it's safe to say that Thanos would have seen Scott Lang coming before he could get near any of his orifices. But in the universe of Marvel's What If...? episode 3, Ant-Man's body infiltration plan succeeded.

More: How Mark Ruffalo In The Incredible Hulk Would Change The MCU

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