It has been theorized the Locust dubbed the Savage Marauders were the first kind of Locust Drones to form any sort of organization outside of the Hollow after the events of Operation: Hollow Storm. They were brutal, bloodthirsty creatures who most often traveled in war parties in their constant search for supplies.
With the success of Operation: Hollow Storm, the Locust homeland of the Hollows was flooded, forcing any surviving Locust to take flight to the surface world. Many of these Locust weren't able to join up with the Locust Queen-aligned remnant of the Horde, descending in ferality. The Savage Marauders, made of former Locust Drones, were the first among their number to form any sort of organization outside the Queen's Remnant with their patchwork raiding parties; they ultimately became a sort of "precursor" to the Savage Locust.