The history of this reality was similar to Earth-199999 until Janet Van Dyne contracted a virus from the Quantum Realm, when Hank Pym went to the Quantum Realm to save his wife. She infected him and both returned to the regular sized world, spreading the virus throughout the Earth. The Avengers reassembled to try to stave off the advancing zombie horde but were overwhelmed by them and turned undead.
- Prior to being given an official reality number, this universe was known as Earth-TRN893 as part of our Temporary Reality Numbers classification system.
- This is the second reality that features zombies in the Marvel Cinematic Universe, the first being Earth-TRN808.
- There is probably another alternate reality of this universe since Doctor Strange Supreme attracted several zombies along with infected heroes who had already died from this universe. 
- 1 appearance(s) of Earth-89521
- 32 image(s) of Earth-89521
- 30 characters that originate from Earth-89521
- 2 teams that originate from Earth-89521
- 4 organizations that originate from Earth-89521