Grunts

Grunts are the lowbiest of lowbie enemies. These foot soldiers for the Covenent are poorly armored and usually poorly armed, packing plasma pistols, needlers, and plasma grenades. (Late in the campaign you'll run across perhaps half a dozen Grunts that wield fuel rod guns, but they're very rare.) They're also quite cowardly, and will usually run in fear if you happen to kill the Brute that stands guard over their squad.



Grunts come in different colors, which roughly denote their varied strengths. Even on Heroic difficulty, though, you're unlikely to notice any real difference in strength between the various Grunts, although there are rare gray Grunts that have significantly more health than the other types.
Some Grunts can be driven insane by the pressures of combat and will ignite plasma grenades in their hands and rush towards you. Shoot them before they get close, or they'll blow you to pieces.

Jackals

Jackals are the regulars of the Covenent army, and usually arrive in one of two forms. The rarer form is the sniper. These guys sit back on cliffsides and balconies in support of a Brute/Grunt squad, usually with a beam rifle or a carbine in their hands, and will take potshots at you. It's important for you to identify them and take them out before proceeding into combat with the squad they're attached to. Usually they'll start firing at you as soon as they're alerted to your presence. If you find yourself under fire from above, immediately backtrack to cover and start zooming in on the cliffs above you to find your adversary and shoot them.
More commonly, however, Jackals will appear with power shields in front of them and will fire on you from a narrow slit on the side, usually using a plasma pistol for the task. The shield will protect them from most damage, so killing them can be tough. If you can get close, landing a grenade anywhere near them will cause them to turn away, letting you fire on them. If you're using a precise weapon, however, you can actually aim at the firing hole on the right side (as you're viewing them). It's small, but you can hit it; a sniper rifle shot will kill them if you hit them here, and any other weapon hit will cause them to recoil, momentarily dropping their shields and allowing you to blast them with a headshot.

Brutes

Brutes are your primary foes throughout much of Halo 3. Although Grunts will be more numerous, Brutes will be more deadly. Although Brutes will possess a wide variety of weaponry, they all have one thing in common: body armor that will protect them from damage until it's removed. As with Elites in the previous Halo games, you need to knock this armor off (preferably with plasma-based weapons), then finish off the meat inside (preferably with bullets). One weapon in particular is great at taking down Brutes: the needler. If you can fire off a clip at most Brutes, they'll die right quick. Grenades also work well, especially the varieties that can stick onto your opponents, but then again, most Brutes will be good about diving away from your grenades.

There are a few different varieties of Brutes, from the lowliest (usually clad in blue armor) to the toughest chieftans (armored with yellow plating). The lower ranks will often be found commaning squads of Grunts; if you can kill them, then their Grunt soldiers will often flee in disarray. Mid-level Brutes will usually be found in groups, and will be a formidable challenge; these groups are when you want to bust out your grenades or explosive weapons.
The chieftans are a breed apart; their yellow armor will prevent you from sticking plasma or Brute grenades onto them (they'll bounce right off), and they'll often wield powerful weapons like the gravity hammer, the fuel rod gun, or dismounted turrets. They'll also usually use the Invincibility equipment just before wading into battle, making them impossible to kill for ten or fifteen seconds or so. Nothing to do then but run away!



Drones

Drones are rare, but annoying. These flying buzzards will descend from the skies and attack with plasma pistols more often than not. Individually they're not very difficult to defeat, but since they attack en masse they can dish out a lot of damage in a small amount of time. Their flying capabilities also usually makes them immune to grenades unless you get a lucky stick.
In most cases, it's best to let your teammates deal with the Drones, or just attempt to run past them while they're firing at another target. If you do need to fire on them, use a weapon that fires rapidly, like the plasma rifle or the assault rifle.

Hunters

Hunters are also fairly rare, only appearing perhaps three times throughout the game. Hunters always appear in pairs, and attempt to fire on you with their massive green lasers before they close in for the kill with their melee attacks. Hunters are tough and incredibly well-armored, making them difficult foes to bring down.

The best way to kill a hunter is to attack it from the back. If you get close to it, it will start to swing its fists at you. Strafe around it as best you can and unload a shot to its unprotected backside (or stick a grenade on there). Just be careful, though, as they often will attack backwards over their heads in retaliation.
If you find that you truly can't take down a Hunter, you can always run away. This probably won't work on the first encounter, but they don't seem to pursue you if you run from them after you encounter them the second time during the campaign.

Flood

The Flood consists of three basic creatures, although one of these is more complex than you might originally assume.

Parasites

The parasitic form of the Flood is a small, seemingly harmless creature that comes at you in waves of dozens at a time. Individually, they're not tough, and will bounce off your shields for minor damage. En masse, however, their shield damage will accumulate and can quickly overwhelm you. If you shoot one of these guys, they'll explode, which can lead to chain reactions when a bunch of them are clumped together, as they often will be.
Parasites will attempt to find dead bodies in their vicinity and reanimate them as Flood zombies. This isn't always avoidable, as the parasites themselves are tiny, fast-moving targets and difficult to shoot.

Flood Zombies

Zombies are the Flood's way of taking over the universe; the Gravemind never met a corpse it didn't like. When a parasite infects a corpse, it becomes a zombie and shambles about, looking for more corpses to create for the parasites to infest. These zombies are dullards compared to their former selves, but retain their speed and ability to fire weapons, and even the energy shields of their former selves.

Zombies should be approached with caution, but are generally fairly weak. If you can overcome their shields, they'll usually go down quickly; dual plasma rifles are ideal for the purpose of chopping through them. It's very important that you keep firing on the zombie, even after it dies again, until its body disintegrates. That'll rob the parasites of another host to infest. If you only hit a zombie until it falls down, it'll eventually just get regenerated to full health by a parasite. If you want to save ammo, just use melee attacks on the corpses until they explode. If you're using an energy sword, attacking corpses uses no ammo.

Changelings

Some of the higher-level Flood creatures have evolved to a point where they can change shape. These guys have three forms, and can change almost at will. They'll often shift based on your behavior.
Stalker: In stalker form, the changeling will become a spider-like creature that sticks to walls and searches you out. You'll often encounter changelings in this form first, before they're aware of your presence, and that's a good thing, as the only attack is a weak melee attack. Shoot them quickly or use your own melee attacks before they jump away and shift.

Hunter: Resembling the Covenent Hunters, the changeling form is even slower and possesses no ranged attacks. They do have a lot of health, though, and can take quite a bit of damage before dying. Use an energy sword on this form if you can.
Ranged: In ranged form, a changeling will attach itself to a wall and shoot numerous spikes at you from a long range. This is by far the most annoying of the forms, as the changelings are often impossible to hit with weaponry at this point, forcing you to switch to a ranged weapon to take them down. Dual plasma rifles will do the job, so long as you aren't too far away, as will a carbine. If you can get close, a sticky grenade will work well.

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