Before Avengers: Endgame landed and we were all whisked away into a series of problematic time travel adventures the going theory on how the Avengers were going to defeat Thanos was that Ant-Man would fly in his butt when he was super tiny and explode him from the inside. While gross, it actually had some validity, I thought. I was clearly wrong, as the film’s writers, Christopher Markus and Stephen McFeely, recently explained on the Empire Podcast. When asked about the Thanos Butt attack Markus revealed:
“Thanos could take a punch from the Hulk, we’ve seen that. And it stands to reason his whole body is at least as strong as that. If Ant-Man expanded, he would be simply crushed against the immovable walls of Thanos’ mighty rectum.”
Obviously, that excuse was given by plenty of folks before Markus said it, but now that he has I think it becomes canon. See, they wrote the movie so they make (or help make) canon, and thus their word goes. Of course, this opens up a whole other can of worms about his digestive system and how it could even eat anything, but we’re probably diving a little too deep in minutia there. Clearly, the only real way to defeat Thanos was to invent time travel, travel back in time, screw up the time travel plan, have the earth invaded, duke it out with everyone and then have some people die. And we know that was the only way because Dr. Strange says so. Hell, he probably saw the Ant-Man in Butt strategy play out in all its gruesome failure.
I mean, there is, of course, another reason they didn’t go with that ending too: no one wants to watch that shit. Literally. Think of all the shit they’d have to show on the screen. No, they made the right choice.