The Halo franchise is home to some of the most iconic enemies in all of video game history. Evolving with each Halo entry, The Covenant takes center stage in the original Halo trilogy and most of its spinoffs, with most Halo media being set during the Human-Covenant War or shortly thereafter. Elites, Grunts, Brutes, Drones, and Jackals, The Covenant has no shortage of instantly-recognizable foes at its disposal, but there's one species in the Halo universe that poses a greater threat than all of The Covenant's forces combined, and that's The Flood.