Over the course of two films, the Avengers struggle to defeat Thanos, as he acquires absolute power by collecting the infinity stones.
Eventually, he is defeated when Tony Stark (Robert Downey Jr) weaponises the infinity stones against him.
According to the popular theory, Ant Man should have been able to shrink down to minature size before climbing into Thanos from below and expanding inside of him.
Marvel directly alluded to the idea in a new video starring Rudd and his Ant-Man co-star Evangeline Lilly, which was shown on the Disney Wish cruise.
“Before we start, let me address the elephant in the room,” Rudd says, in character as Scott Lang. “There’s a lot of chatter out there asking why I didn’t shrink down, go in and er… kill Thanos, in a really creative way.
“First of all, gross,” he continues. “Secondly, it’s much more complicated than that. Allow me to explain…”
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At this point, Lilly’s Hope van Dyne interjects, saying: “If only we had the time!”
The footage has been shared on social media via fan-captured video.