Unggoy Heavy

Grunt Heavy is a Covenant Unggoy (Grunt) rank. This rank is designated for use of heavy weapons and turrets, it has nothing to do with personal weight.

Armor
Heavy Grunts wear distinctive green armor with methane breathers, but are otherwise similar to other Grunts in terms of armor style. They take much more damage than Grunt Minors and Grunt Majors, but not as much as higher ranked Grunt Ultras and SpecOps Grunts.

Combat
Heavy Grunts are usually seen in conjunction with other Covenant infantry, operating as heavy support units, and usually operate heavy weapon systems such as Plasma Cannons, Shades, and Fuel Rod Cannons. They will usually will not flee from their position until the player is too close or out of range of their weapon, in which case they will pull out a Plasma Pistol and attack like a normal Grunt. They are easily dispatched using most tactics, though their armor seems to be tougher than the average Grunt, most likely to protect them from explosives and other heavy weapons fire. Unlike most Grunts, they will rarely throw Plasma Grenades.

Note that the cannon is free for you to use after taking out its operator. In Halo 2 a Heavy Grunt must first deploy its Plasma Cannon before it can be used. If the Grunt Heavy carrying the Plasma Cannon is killed before it can deploy it then it cannot be used. This is not the case in Halo 3 since most of the Plasma Cannons encountered are already deployed with the exception of few, and can still be used even if they are detached from their tripod.

In Halo 2, their armor is turquoise, but in Halo 3, their armor is a more emerald greenish color.

In Halo 3 Grunt Heavies are seen utilizing many different heavy weapons and vehicles. They are commonly seen driving Ghosts, and seem to be very skilled drivers, especially on higher difficulties. Grunt piloted Ghosts can be a fearsome presence on the battlefield. Grunts will attempt to ram enemies and will keep their distance from advancing foes. Usually if they're not piloting a Ghost then they're manning a turret or carrying a Fuel Rod Cannon.

Like SpecOps Grunts, they are some of the most dangerous Unggoy. When not manning a vehicle or turret or carrying a Fuel Rod Cannon, Grunt Heavies will usually use Plasma Pistols. They are very efficient with these weapons, even overcharging them which is uncommon among Unggoy. They will even try to aim for Headshots, even though none of the weapons they are encountered using are capable of getting one

Grunt Heavies are fearsome enemies, especially on the Heroic and Legendary difficulty settings where their heavy weapons can make short work of the player. Their lethal efficiency with anything they use has coined the term "Green Grunts are Horrible People"; a widely used term on Xbox Live.

Appearances
Heavy Grunts have been seen in Halo 2 and Halo 3:

Halo 2

 * Cairo Station - Two Heavy Grunts at Hangar A-02 and three at Commons B-01 man Plasma Cannons.


 * Outskirts - Three Heavy Grunts are found manning plasma cannons in the tunnel.


 * Delta Halo - A handful of Heavy Grunts man Shielded Plasma Cannons at the beginning of the level, defending against attack by SPARTAN-117 and Orbital Drop Shock Troopers.


 * Gravemind - Several Heavy Grunts are deployed to take out the Master Chief, all are equipped with the deadly Fuel Rod Cannons, except for the two Gunners at the start of the level.

Halo 3
Any level that an other than the Covenant enemy phantom appears. They are seen controlling the turrets of it most of the time.


 * The Storm - Seen in on Scarab on higher difficulties manning plasma turrets and on the last part of the storm carrying a plasma turret will set it up when his comrades sees you when you go to take out Covenant AA gun.


 * The Ark - Seen in many points throughout the level, they drive many of the light vehicles and operate plasma cannons from many positions, including two atop a Gravity Platform in the beginning area. There are also two with Fuel Rod Cannons half way into the level.


 * The Covenant - Depending on the difficulty, two Heavy Grunts armed with Fuel Rod Cannons defend each of the hallways that lead to the Prophet of Truth. The first area in the hallway, on Legendary, 2 heavies, one with a fuel rod, the other with a turret will arrive as reinforcements.


 * Most Shades in Halo 3 are operated by Heavy Grunts, appearing in most levels.

Trivia

 * Very rarely they can be seen with Spikers. This is easier to find should the player destroy a Phantom, the Grunt will most likely (if it had had survived) be sporting a Spiker.
 * The only time a Grunt Heavy is not seen deploying a Plasma Cannon in Halo 2 is at the beginning of the level the Arbiter, where a SpecOps Grunt is seen carrying one. This is because the only Unggoy allies encountered in the level are SpecOps Grunts.
 * It is easier to see Grunts with Spikers in Theater Mode on The Storm where you can pause and look at them carefully.