The phrase "what if zombies" most notably refers to the Marvel Studios animated series episode titled "What If... Zombies?!" from the first season of the series What If...? This episode explores an alternate Marvel Cinematic Universe (MCU) reality where a quantum virus turns many Avengers into zombies, causing a widespread zombie apocalypse. The story follows survivors searching for a cure amid this chaos. The episode is based on the Marvel Zombies comic series and was released on Disney+ in September 2021.

Following the popularity of this concept, Marvel Studios announced an upcoming adult animated miniseries called Marvel Zombies , set five years after the events of the "What If... Zombies?!" episode. This series, debuting September 24, 2025, continues the story of survivors battling superpowered zombies in a dystopian landscape within the MCU animated universe, and it will be rated TV- MA for mature audiences.

To summarize:

• "What If... Zombies?!" is a Marvel animated episode imagining a zombie apocalypse within the MCU.
• It inspired a new miniseries Marvel Zombies released in late September 2025, expanding the story about survivors fighting zombie Avengers.

If more details about the plot, characters, or specific zombie scenarios are desired, those can be further explored.