|“||Ages ago, the other pony tribes united and left us in the cold. We Thracians have endured without friendship. Thrived! And now Equestria's reliance on it shall be their downfall.||„|
|~ King Diomedes expressing his desire to conquer Equestria.|
King Diomedes is an antagonist in the My Little Pony: Friendship is Magic comic series and the overarching antagonist of Feats of Friendship saga. He is the ruler of the Thracian Pony tribe and father of Swift Foot, the main antagonist of the saga.
Diomedes is a adult male Thrace pony (which is identical to an Earth pony) with a grey coat and yellow eyes. He also has long, white hair, a thick beard and a tail tied in braids. He wears Grecian royal attire and a crown shaped like his cutie-mark, which is similar to the symbol of his kind.
Diomedes is a ruthless tyrant, even to his own children. He also has a deep hatred for the other pony tribes and seeks to conquer them through any means necessary. Diomedes also despises friendship, seeing it as a weakness.
As the ruler of the Thracian pony tribe, Diomedes has full control over all within his kingdom. He also has a telepathic link with others, particularly with Swift Foot.
At some point during his reign, King Diomedes decides to conquer Equestria, and plans to do so by destroying its friendship with each other and the other races. To this end, he sends his eldest daughter and most trusted soldier, Terri Belle, as a spy and learns that Princess Twilight is hosting the Feats of Friendship competition. Seeing this as an opportunity to destroy Equestria's friendship, he orders two other daughters of his, Blonn Di and Shining Light, to summon his youngest daughter, Swift Foot to him, which they purposely took their time doing so she would be late. After scolding Swift Foot for being tardy, he expresses his desire to conquer Equestria and demands that Swift Foot infiltrate Twilight's School of Friendship in order to make this desire possible, since Terri was too old and the middle sisters too incompetant. Though hesitant of this, Swift Foot accepts this mission in fear of her father's wrath.
During her stay at Twilight's school, Swift Foot makes several reports to King Diomedes on her successful infiltration, up until she realizes how powerful friendship can be.
- King Diomedes shares his name with the historical figure in Greek/Roman mythology, who also ruled over Thrace and trained his horses to be man-eaters, but then met his end when he was tossed into them by Hercules.