The question is pretty cut-and-dry. How to most efficiently kill the breeder(aka the first boss) on Nightfall?
The best way to defeat the breeder on nightfall in Call of Duty:Ghosts Extinction
call-of-duty-ghosts
Related Solutions
Speed:
Quickdraw – aim down sight faster
Sleight of Hand – reload faster
Agility – move faster
Marathon – sprint for longer
Stalker – move at faster while aiming down sights
Handling:
Strong Arm – throw grenades farther, decrease the cook time of grenades
On the Go – reload while sprinting
Reflex – switch between primary and secondary weapons quicker
Steady aim – increased hip-fire accuracy
Dexterity – weapons ready faster after sprinting
Stealth:
Takedown – killing enemies won’t reveal their death skull to team mates
Blind Eye - provides stealth against aggressive killstreaks
Off the Grid – immune to SAT-COM and radar pings
Dead Silence – make less/no noise
Ghost – no red name when targeted
Awareness:
Recon – spot enemies through explosives and hitmarkers
Scavenger – resupply
Sitrep – detect enemy equipment
Awareness – hear enemies easier
Wiretap - upgrades your SAT-COMs by hacking into active enemy SAT-COMs
Resistance:
Lightweight – no fall damage
Painkiller – faster health regeneration
Toughness – less flinch when shot
Tac Resist – resistance to flash, stun and EMP effects
Blast Shield – increased explosives resistance
Equipment:
Tac Reset – extra tactical grenade
Lethal +1 – extra lethal grenade
Fully Loaded – max ammo capacity
Three attachments on primary weapon
Danger Close – increased explosive damage
Elite:
Gambler – 1 random perk
Hardline – earn Killstreaks quicker
Ping – when you kill an enemy it will locate enemies near by the body
Overkill – choose two primary weapons
Deadeye – consecutive kills increase the chance to deal more damage with guns
The trophy system in Ghosts extinction mode nullifies the ranged projectile launched by Scorpion enemies. Here's the quote from the COD wiki:
The Trophy System returns in Call of Duty: Ghosts's multiplayer. It is also available in Extinction mode (where it is simply called "Trophy"), where it destroys the Gas Clouds attack from Scorpions, and it will not be attacked by Aliens.
I've used these quite a few times, they very helpful in keeping an area clear of the scorpion's gas. Since the gas damages almost everyone on your team, a well-placed trophy can benefit the whole team. They come in handy for times such as repairing the drill. Just set the trophy (system) near the drill and it will destroy a few of the gas projectiles before being destroyed. I'm not sure the exact number of projectiles it will destroy, but I've observed it to be around 2-5 projectiles.
Sources: Personal experience playing COD Ghosts Extinction and the links in the answer above.
Best Answer
It'll charge up and spew a barrage of bullets your way. When you see it prepare for this, find cover – behind a building, under some rocks, anywhere. Otherwise, you'll be instantly killed by the gunfire. The beast also fires red orbs from its tail, which rain down toxic mist in certain areas of the map. Watch where these attacks go, and avoid these areas until they're clear. Otherwise, you're dead. It also launches yellow eggs that hatch aliens, and they're a pain to deal with while focusing on the Breeder. Destroy them as soon as you can.
Sentry guns are a huge asset in this fight, provided they're facing the Breeder head-on, since its face is the primary weak point. Shoot him only in the red part of his face. Otherwise, save the turrets for secondary duty, like wiping out eggs.
Use your special weapons from the lockers whenever you can. Eventually, the Breeder will make a run for it, and you'll need to face off against a horde of aliens before running into it again. Destroy the last of the Hives as soon as possible, as you'll want to make sure the area is clear of smaller aliens before running head-on into the Breeder.
Deal more damage to the Breeder when it returns, but watch out for waves of enemies when it climbs up the building (usually when it’s down to half damage). It's here where you'll utilize your special weapons, as well as turrets to survive the fight. The Rhinos are particularly tough when they charge, so be prepared to move quickly.
As the Breeder returns, keep an eye out for flower-shaped Hives on the ground. These are small and easy to miss, but they are essential for the Breeder to continue fighting, as they act as fuel. Destroying them will assure it continues taking damage, so make them a priority while avoiding the Breeder's attacks.
For weapons choice MK32 grenade launcher, Maverick, LSAT. BUT make sure you hit it in the face or you're just shooting tampons.
TL;DR: