Also known as 'Earth-A', Earth-721 is home to a Reed Richards that became the rocky Thing and a Ben Grimm that became the stretchy, flammable Mr. Fantastic. It was briefly visited by the Thing (Ben Grimm) of Earth-616 and became involved in a scheme by Arkon to pit three worlds against each other in nuclear wars. Despite the presence of a Thing and Mr. Fantastic, almost no natives of Earth-721 have any superpowers. A scientist from Earth-A created a device that would allow his fellow 721 inhabitants to travel to Earth-616 and transform into their superpowered counterparts, complete with all their powers and paraphernalia. Once this clandestine replacement of Earth-616's superhumans was discovered, the Reed Richards from both universes quickly set to work sending both abductors and abductees back to their home universes, before destroying the dimension-crossing device.
- Characters from Earth-721
- Other things related to Earth-721
- Earth-721's Appearances
- Earth-721's Minor Appearances
- Media Earth-721 was Mentioned in
- Images from Earth-721
- Reality Gallery: Earth-721