|Debut appearance:||Secret Avengers Vol. 1 #33|
|Rick Remender, Andy Kuhn|
|Secret Avengers Vol. 1|
Earth-666 is a reality were Earth is populated by different subspecies of undead monsters.
The history of this Earth is unknown.
However, it is currently in a unique position, as its populations is divided between a variety of subtypes of undead: vampires, werewolves, mummies and others. The divide between the various groups is social and deep-rooted, with parts of the world ruled by various factions. However, there is some hope in this world, as the greatest heroes of the various groups are unied to protect the world as the Avengers of the Undead.
- This reality was originally labelled in solicitations as Earth-4680