The planet of Mammord was made by the gods of the Fourth World to guard the frontiers of the universe against Mageddon. They made a hero, Adam One, and sent him out to tame Mammord. In time, Mammord became Wonderworld, and was the headquarters of a guard of heroes who stood against Mageddon.
The entire was covered by a city called Omnitropolis, which included a Museum District full of the spoils of the Wonderworlders' many adveturers. Ultimately, the world was destroyed by the immensity of Mageddon, though The Glimmer survived long enough to help the super-champions of Earth stop the Warbringer once and for all. After the events of Flashpoint restructured the Multiverse, the remains of Wonderworld now reside within the Speed Force Wall acting as the border between the Bleed and the Sphere of the Gods.
- Adam One – the original hero of Mammord, charged with taming the planet. Considered a true hero. His skin appears to be made out of patches of rusty iron.
- Nightmare – a being who bears the visage of a horse's skull. His method is to fight evil directly, in the subconscious minds of criminals, usually in his Nightmare Craft. He is accompanied by a younger sidekick named Nemo.
- The Glimmer – a giant blue speedster, he has the power to summon "lightning and chemicals" and run across time itself. He went missing some time before the "Rock Of Ages" storyline. He used a Hyperwheel built by the Blacksmiths of Mammord to augment his powers.
- The Mote – the caretaker of the Museum District, he has the power to make himself smaller. He is the second-last survivor of Wonderworld.
- "The Blacksmith" – the last of the Blacksmiths of Mammord, he operated the Hyperwheel in the absense of the Glimmer. His skin is as black as coal and his hair is a mass of fire. He died when the Mageddon Effect caused him to fight Adam One.
- "The Goddess" – the only noticably female member of Wonderworld's High Council, she has four arms. In one hand she carries a suckling babe, and in another she carries a war-spear. She has a brash style of negotiating.
- "The Robot" – a pale blue being with a deep blue fire about its head. Its mode of speech is somehow technological.