Covenant ships are the warships of the alien Covenant alliance in Halo, Microsoft's long-running science-fiction shooter series, where the artificial intelligence Cortana often warns the player about approaching threats. Clips of her warnings have circulated among Halo fans for years, shared as short soundboard sounds for gameplay videos, memes and reaction edits. The line remains popular because it instantly signals danger from an unseen enemy, giving creators a recognisable piece of Halo audio that needs no explanation for fans of the games.