Cupil is a unique, mysterious creature who serves as Fina's loyal companion in the game Eternal Arcadia (known as Skies of Arcadia in English). Cupil is a shape-shifting being with a friendly and curious nature, often providing comic relief throughout the story. While Cupil does not speak, it plays a crucial role by aiding Fina in battles, transforming into various weapon forms. As a non-human character, Cupil supports the main party and symbolizes the connection between Fina and her ancient heritage.