Yūsaku Komiyama is writing and drawing the story, which begins with the Avengers gathered to throw Tony Stark a surprise party. A horde of zombies crashes that party, and some of the Avengers become infected while trying to contain the outbreak.
An "Episode 0" one-shot prequel to Avengers: Age of Ultron was released in Weekly Shonen Jump earlier this month. Prior to that, the Avengers were featured in an Attack on Titan crossover manga. Unlike that crossover, there are currently no plans to officially release Zombies Assemble in the United States.
Check out preview images in the gallery below (via CBR).