Unggoy holdouts were Unggoy soldiers formerly of the Covenant who had been abandoned by their invading fleets following a Human world's destruction. Built up of thousands of loosely organized clans and tribes, the Unggoy holdouts were formed with either the mutual idea of basic survival, to even the out-right rebellion of Covenant virtues and a surrender to the UNSC side. The holdouts were largely unknown about throughout the war by either side, the UNSC having left their own destroyed worlds far the earlier and the Covenant Fleets having expecting them to have their abandoned to have died. Nevertheless, rumors abounded on some of the semi-ravaged Human worlds of mysterious bandits lurking in the caves and woods, but not until the recolonization of the colony worlds restored by The Emissary would their entire presence become known.