Opal Koboi is a fictional character from the Artemis Fowl series by Eoin Colfer. After the character's introduction in the second book in the series as a supporting antagonist, Colfer again used Koboi as the main antagonist of the fourth, sixth, and eighth books in the series, giving her the status of archenemy to Artemis Fowl II. She is voiced by Hong Chau in the 2020 film in an uncredited capacity (dubbing over stand-in actors Emily Brockmann, Jessica Rhodes, and Charlie Cameron), physically portraying the character in a deleted scene.