The world of Marvel Comics is loaded from top to bottom with characters and story arcs that are ripe for adaptation. With the Marvel Cinematic Universe going buck wild with the whole multiverse concept throughout the 2020s, "What If...?" gave the team at Marvel Animation free rein to experiment and play around with stories that don't immediately impact the central canon of Earth-616. One of the show's most surprising episodes came in its first season with "What If...Zombies?," a loose adaptation of Robert Kirkman's "Marvel Zombies" comic metaseries that originated in Issue 21 of "Ultimate Fantastic Four." It posits a scenario where Janet van Dyne got infected in the Quantum Realm with a virus that transformed her (and a significant portion of the Marvel characters) into flesh-eating zombies, with only a select few heroes remaining.
Instead of the "What If...?" episode being a one-off, it ended up becoming the springboard for an animated spin-off called "Marvel Zombies" on Disney+. The key difference between the two is that, while the four-episode event series is a continuation of that story, it's explicitly made for an adult audience, with significantly more gore added to the mix. Among the roster of non-infected heroes are Shang-Chi (Simu Liu), Kamala Khan (Iman Vellani), Riri Williams (Dominique Thorne), and Yelena Belova (Florence Pugh), in addition to other members of the Thunderbolts/New Avengers. It largely features a lot of names we've seen before, but that doesn't mean we won't see any new faces.
The behind the scenes issues with Marvel Studios' "Blade" reboot have been so ongoing that the beloved daywalker has been reprised by Wesley Snipes in "Deadpool & Wolverine" and a Moon Knight-inspired variant (Todd Williams) in this show before Mahershala Ali could make his first live-action appearance. The Academy Award-winning actor's brief voice cameo in "Eternals" counts as much as that movie does to the MCU at large (not much). As for the rest of potential superhero appearances in "Marvel Zombies," you have to imagine they're saving any new potential supers in secret until the series comes out. There's at least one candidate from the horror-adjacent comic series, however, that is all but guaranteed to never show up, and I don't think that's very groovy.
That's right, Bruce Campbell's Ashley J. Williams, the boomstick-wielding Deadite slayer from Sam Raimi's beloved "Evil Dead" series, is technically part of the Marvel universe by way of the 2005 comic miniseries "Marvel Zombies vs. The Army of Darkness."