Earth-38723 is an alternate universe that is extremely similar to the Earth-616 and 9022 realities. It features both classic heroes such as Iron Man (Tony Stark) and Captain America (Steve Rogers), but also includes other heroes that are not a part of Earth-616's past, such as the Buzz and Spider-Girl. The most notable change about this universe is the fact that Timothy Parker was bitten by the radioactive spider that would've bitten Peter Parker, Tim's uncle in this universe, causing him to become Spider-Man.
History
In the Beginning
Millions of years ago, the Kree landed on Earth and begin to subject a select group of early humans to genetic experiments, creating the first generation of Inhumans. After years of experimentation, the Kree place the Inhumans in cryogenic storage in an underground location and depart from Earth.
The First of the Mutants
There wasn't another superhuman subject for thousands of years afterwards until the first ever mutant, En Sabah Nur, was born in Egypt. Eventually, Nur became the immortal ruler of ancient Egypt and lived by the philosophy that only the strongest should survive. He also discovered technological remains of the Kree armada that arrived on Earth before and enhanced himself, and his empire, with this technology. Eventually, Nur, dubbing himself Apocalypse, placed himself in a state of cryogenic suspension and waited for millions of years, hoping to awaken in a time where mutants would be prominent. Nur eventually awakened in 1865 and encountered Dr. Essecs, who claimed that Apocalypse was the first of a new race of super-mutants. Essecs agreed to aid Apocalypse in his plan to wipe out most of the human life on Earth in exchange for eternal power. Apocalypse then transformed Essecs into Mr. Sinister, another immortal with telekinetic powers.
The World's First Avenger
In 1942, the United States had entered World War II.