The Tremor Mace is the main weapon belonging to the Iron King that has the power to shake the earth and can go up against very powerful weapons such as Monkey Khan's Atom-Bat. He used it during Sonic the Hedgehog and Monkey Khan's "reconnaissance mission" to help drive them back from New Megaopolis with the aid of the Dark Egg Legion and the Yagyu Clan. Despite the power of this weapon, it proved unable to defeat the defensive shields of New Mobotropolis when the Iron King attempted to pursue the Knothole Freedom Fighters after they had captured Dr. Eggman. The Piko Piko Hammer wielded by Amy Rose also proved a match for the Tremor Mace's fearsome power; blocking a full-power swing aimed at Monkey Khan when the Iron Dominion was conducting their invasion of New Mobotropolis and again while freeing the Mobians in the Arena from being "Legionized," this time to protect Geoffrey St. John. The mace was later left behind in New Mobotropolis when the Iron King was sent flying out of the city by the power of the Fan of Fen Xing. (StH: #202, #206, #208, #209, #210, #211)
- Although appearing to be magical in nature, it is possible the Tremor Mace is a technological weapon made by Dr. Ivo Robotnik, similar to the Atom-Bat. Seeing as the Iron King was not seen with it in his earlier years, it might have been part of the supplies provided by Robotnik Prime later on in his career. It could possibly releated to the Atomic Mace Ixis Naugus created before leaving for the Zone of Silence.
- Presumably, in the new continuity, the Tremor Mace no longer exists.