Horde Event

 Horde:  is a event quest in Fallout 76.

Quick walkthrough
When the quest begins, travel to the location where it is marked on the map. Once there, the objective will change to either taking out the legendary version of the enemy responsible for the horde, or search through four locations for where the horde leader is hiding. As a player character checks the areas, if the boss is there, the objective will change to going into the location interior and eliminating them, or if not, be granted some experience from checking the location and move on to the next one. Once the legendary enemy and horde boss is dead, the quest is completed.

Detailed walkthrough
When the quest starts, head to the starting point for it marked on the map. Once there, one of two things will happen next:
 * Search four locations for the horde boss
 * Eliminate the horde boss before they can spawn more of their kind.

If the objective changes to eliminating the horde boss immediately, the boss will be a legendary enemy surrounded by several non-legendary enemies serving as its bodyguards. Killing the horde boss completes the quest immediately.

If the objective changes to searching for the horde boss, four locations will be marked around the region where the quest took place. Investigate each one to see if the horde boss is hiding inside within the interior area of the location. If the horde boss is there, the objective will change to heading inside to slay them. If not, experience will be granted for searching the location and the remaining locations will need to be checked to follow up on pinpointing the horde boss' location to eliminate them. Once the boss is found and terminated, the quest is complete. Mop up the stragglers and scavenge the bodies for any worthwhile loot alongside the legendary item on the horde boss.

Possible horde types

 * Angler
 * Feral ghoul
 * Liberator
 * Protectron
 * Wolf - Note: Only appears if Leader of the Pack is completed first.
 * Super mutant
 * Mole rat