|List of all weapons & other items|
Thundrainium Mace is a spiked battle club that is the primary weapon of Grune the Destroyer. After being accidentally released from his prison by a couple of Bolkins, Grune locates the Thundrainium Pits of Third Earth and forges the mace from the radioactive "Fire Rocks". Because it is made entirely of Thundrainium, the mace has an eerie yellow glow around it.
Grune uses the Thundrainium Mace to battle Jaga and the Thundrainium in it severely weakens Jaga, giving Grune the upper hand. Fortunately, Lion-O gives Jaga the Sword of Omens as well as his strength and the elder ThunderCat manages to disarm and defeat Grune.