'What If' Marvel Zombies explained: How the MCU changes and adapts the comics

What If...? promised plenty.

The series’ teaser set up touching emotional moments, rapid-fire jokes, and, yes, that looming Watcher. But only one moment captured fans’ excitement above all else: Marvel zombies.

It wasn’t clear how, but the Avengers would have to conquer flesh-eating foes — or join their ranks themselves.

What may not be obvious, however, is that much of “What If... Zombies!?,” however fantastical, was ripped right out of comics. Here’s everything you need to know about the new episode.

What If...? was based on a comic series, but the zombies actually belonged to a different series altogether. Whereas most stories of zombie apocalypses focus their action on the few surviving non-infected characters, Marvel Zombies made the titular undead Avengers its main characters, as they came to terms with their own inhumanity.

In the comics, Bruce Banner was turned into a zombie and lost the ability to ever become the Hulk again, given that being undead means no more emotions, including anger. This plot dimension was not preserved in What If...?, with Bruce Banner supplying the audience viewpoint as a new, human visitor to this zombie-ravaged world.

However, plenty of Marvel Zombies touches were carried over to the MCU. Firstly, Scott Lang existing as only a head in a jar, Futurama-style, was inspired by Janet Van Dyne’s fate in the comics. She was zombified, living on as a head floating in a jar connected to a cybernetic body.

The MCU version of the zombies also showcases a different strength specific to What If...? The character design throughout the series has always been a reflection of the live-action films more than their comic adaptations, so this episode and the cartoonishly zombified versions of the Avengers was an artistic challenge unlike any that Marvel had faced before.

Thankfully, Marvel’s artistic team was up for the task. “I think the fun of it is seeing Captain America's helmet that looks pretty much right, but then there's the shrunken, shriveled face inside of it,” Ryan Meinerding, Marvel’s Head of Character Design, told Inverse. “Being able to play with the icons in that way was a lot of fun.”

Another huge comic thread makes for one of the episode’s most heartbreaking reveals: Vision, left with no other choice, is keeping T’Challa captive as a food source for his undead wife, the ultra-powerful Scarlet Witch.

In the comics, Hank Pym keeps T’Challa in the same condition, as a food source for himself. When Janet stumbles upon the secret snack hoard/King of Wakanda, she gets upset. Hank reacts reasonably, biting her head off, which prompts T’Challa to bring said head along as a specimen when he encounters a handful of survivors.

Similarly, in the episode, Vision uses Scott Lang’s zombified head to test out a cure.

Yet another strength of this episode was the heartbreaking voice performance of Chadwick Boseman as T’Challa, one of few survivors of the zombie apocalypse. When Peter Quill grieves his loved ones, T’Challa tells him, “In my culture, death is not the end. They are still with us, as long as we do not forget them.” It’s obvious none of us are going to forget Boseman any time soon, and it was poetic to hear from him in this way.

While What If...? wasn’t able to replicate the comic series’ ability to make the zombies sympathetic, that’s ultimately for the best. We’re used to seeing the Avengers at peak pathos.

This episode gave us a rare glimpse of what happens when they go berserk. Ironically, in “What If... Zombies!?,” Bruce for once isn’t able to control his own transformation into a raging monster. My, how the tables have turned.

What If...? is now streaming on Disney+.