Horace's evil twin was created by Sidney Ruffleberg on orders from Carltron, apparently to take over Antiqua. Several weeks before the start of the game, the evil twin came to Nobilia and rapidly ascended the social ladder to become its ruler. Though Horace himself heard of Nobilia's new ruler, no one including him knew the ruler was his evil twin; the twin almost never appeared in public, delivering decrees and orders through his adviser, Pompolonius.
With his power consolidated, the evil twin announced his next goal was to obtain the power of the Diamond Eyes. Pompolonius warned that the people would not support this without a sign from the Sacred Dog, but the twin mocked such beliefs. At this time the Hero's Dog ran through the palace; bearing an uncanny resemblance to the Sacred Dog, the twin had Pompolonius present the dog to Nobilia as a sign it supported his claim for power. The dog "chose" the hero to face Vigor in Nobilia Colosseum in honor of its presence, and the victorious hero was tasked to find the Diamond Eyes. The twin contacted Carltron to let him know, and was warned to keep an eye on the hero after his interference in Prehistoria.
After the hero found both the Diamond Eyes, the evil twin disguised himself as Horace and met with the hero on the Western Bank to take them. However, the hero realized "Horace" was acting strangely, and pursued him to Nobilia. In Nobilia the evil twin used the Diamond Eyes to revive the town's dog statue as an ancient monster, Aegis. The evil twin vanished, leaving the hero to battle and destroy Aegis.
- The actions of Horace's evil twin inadvertently led to Carltron's defeat; the disposal of Aegis's power core opened a path for the hero to travel to Gothica, the Diamond Eyes were later used to power a rocket to send the hero to Omnitopia, and the Energy Core was used to power a teleporter to Carltron's Lair.