Jun Kun

The Iron King was a Mobian Ox who worked alongside the Iron Queen, an Overlander sorceress. Both of them are enemies of Monkey Khan. The Iron King has an affinity for collecting weapons. Sonic and Tails encountered the Iron King and Queen during their quest for Ixis Naugus, who fled across all of Mobius. Sonic and Tails learned during their trek that the Iron King and Queen crowned themselves ruler of a Mobian settlement. With help from the settlers, the Iron King and Queen were defeated, with the Iron King being blown away by the magical fan of Fen Xing. The Iron King later moved to the ruins of New Megaopolis along with the Iron Queen to take over the Eggman Empire along with Snively Robotnik.

He has brown fur, white eyes, and wears heavy armour made of metal.

Rule of the Iron Kingdom
Sonic and Tails first encountered the Iron King and Queen during their quest for Ixis Naugus, who fled across all of Mobius. When they arrived at Mount Stormtop Village, they learned that the Iron King and Queen crowned themselves ruler of the village. When the villagers refused to swear loyalty to either, the Iron Queen set Mount Stormtop on fire for over a hundred days and would not lift the spell until the villagers agreed to bow down to them. Sonic and Tails were told by Li Yeun that only the magical Fan of Fen Xing could blow out the flames on the mountain. When the two tried to retrieve it, the Iron Queen cast a spell on renegade cyborg, Monkey Khan, to kill Sonic and Tails before they arrived. They managed to free Khan and he joined them in assaulting the Iron King at his fortress. Sonic and the others returned to Mount Stormtop to blow out the flames, the Iron Queen tried to use her magic to stop them but failed and the flames were extinguished. The Iron Queen left the village swearing vengeance on Sonic. (StH: #60)

New Empire
Nearly two years later, the Iron King served as a Sub-Boss to the Eggman Empire over the Dragon Kingdom. The local resistance there were beginning to keep the Iron King and Queen at bay. After the Iron Queen made romantic connections with Snively Robotnik over in New Megaopolis, the Iron King accompanied her along with the Yagyu Ninja where they arrived at the landing bay of the Eggdome via dirigible, with plans to usurp the Eggman Empire following Dr. Eggman's recent descent into insanity. (StH: #194, #200)

Romance
The Iron King's only known romantic relationship is his marriage to the Iron Queen, but it was strictly out of benefit and not romance, which is made all the more obvious by the Iron Queen finding love with Snively. (StH: #60, #194)

Background Information

 * It was stated in the letters page of Sonic the Hedgehog: #71 that the Iron Queen was a Mobian badger. However, writer Ian Flynn stated that he considered her an Overlander given her character design, adding that the Iron King and Iron Queen's "titles are purely honorary and not romantic. They're together out of benefit, not out of romance" and that "having a human [Overlander] female wed to a animal character might raise some eyebrows." (1)
 * The Iron King, along with the Iron Queen, holds the fourth longest non-appearance gap in the main comic series at 140 issues (StH: #60-200), tying them with the badnik Coconuts.
 * The Iron King seems to be based on the Ox King from Journey to the West.