Argos (アルゴス, Arugosu) is the main antagonist of Kamen Rider Ghost: The 100 Eyecons and Ghost's Fateful Moment. He was a prince of the Gamma World royal family who transformed into the first Kamen Rider Dark Ghost (仮面ライダーダークゴースト, Kamen Raidā Dāku Gōsuto) and later Kamen Rider Extremer (仮面ライダーエクストリーマー, Kamen Rider Ekusutorīmā).