Alien Grunt

The Alien Grunts are the primary combatant of the Nihilanth's Xenian army. Tough, strong, and extremely hostile, Alien Grunts stand about 7 feet tall and are armed with a biological weapon called the Hivehand, which contains Hornets, insect-like flying creatures that seek out living targets and attack them. Hornets (also known to some as Thornets) respawn as an apparently infinite supply of ammunition. The Grunt will also use basic unarmed hand-to-hand combat when necessary.

Description
Alien Grunts share many features with their Vortigaunt counterparts: multiple red eyes, backwards-jointed legs, hoofed feet, and a short arm extending from their mid-torso, which is most likely used for feeding. However, they do not seem to share the race's myriad energy-based powers; hence the need for the hivehand weapon. At one point in the game, a group of alien grunts appear to be commandeering, or at least have set up, an alien energy cannon, implying the necessary requirement of external weaponry.

Grunts are also equipped with metallic armour around the groin and shoulders, as well as metal helmets and shoes, though it has been speculated that this is actually a natural 'shell' formed as a result of a calcium-rich diet. Interesting, this armor completely protects the Alien Grunt's back, but is open in the front leaving the Grunt's entire lower torso exposed. In the original Half Life, Alien Grunts takes significantly reduced damage (roughly 50% to 60% of normal) if shot in the armor instead of in their exposed body with a magnum or crossbow. Lower impact rounds, such as pistol/assault rifle bullets, buckshot, and even the primary fire of the tau cannon will outright richochet off the armor without doing any damage at all. This is not true in Half Life: Source, since the source engine does not support different damage values/effects for different materials.

Alien Grunts have roughly twice as much health as HECU Marines (varying somewhat depending on difficulty); combined with their bullet deflecting partial body armor, this gives them high durability. On Normal difficulty, Alien Grunts can take 4 to 5 close range shotgun blasts or up to two dozen rounds of MP5/M4 fire to kill. They also demonstrate superhuman strength in various scripted sequences seen throughout the game; such as punching a HECU Marine through a concrete wall, or quickly prying opening a large set of heavy blast doors. Alien Grunts can be found being transported through a factory on Xen, stored in pod-shaped containers. The implication is that the Alien Grunts are manufactured beings, though it seems unlikely that Xen has the technology to manufacture sentient beings.

Trivia

 * If the player chooses not to accept G-Man's offer at the end of Half-Life, he will put him (unarmed) into a large room full of Alien Grunts.

List of appearances

 * Half-Life
 * Half-Life: Opposing Force
 * Half-Life: Blue Shift
 * Half-Life: Decay
 * Half-Life 2: Raising the Bar