Headcrab
A headcrab is a fictional alien parasitoid found in the Half-Life and Half-Life 2 computer game series created by Valve Software. Headcrabs are also referred to as head-humpers by Barney Calhoun and parasitics by the Combine Overwatch. They are the most numerous and arguably most iconic aliens in the series.
At present, there are three different headcrab variations (two of which were introduced in Half-Life 2), all possessing the ability to attach to humans and transhumans to form zombies. While appearing similar to the original headcrab, both headcrab variations differ in a sense that they strictly use their four longer limbs for movement, attacking and standing, as opposed to the generally shorter limbs from the original headcrab.
Standard headcrab
Physical description
Often referred to as a normal, original, or classic headcrab to distinguish it from the other two headcrab species, the standard headcrab is a small creature consisting of a rounded body with four legs for movement (two stubby legs at the front, obscured by its claws, and two hind legs at the back; see picture) and a pair of larger frontal claws for attacking prey or as additional support when standing still. Under the headcrab's body is a large rounded mouth surrounded by pointed flesh (which also includes the headcrab's stubby front legs) with sharp claw-like "beaks." Standard headcrabs have a mottled tan-coloured skin and reddish legs.
In Half-Life, the standard headcrabs are shown to be the offspring of a giant creature named Gonarch (also known as "Big Mama"), which shares similar physical qualities with headcrabs. Underdeveloped "baby" headcrabs spawn at a rapid rate from a sac that dangles beneath the creature.
The design of the headcrab changes between Half Life and Half Life 2, with the original headcrab having exposed teeth and intestines at their mouth, while the Half Life 2 version does not. As such, it is initially apparent that the headcrab only walks with its large front claws and hind legs, while the stubby legs form part of the headcrab's mouth. The headcrabs found in Half-Life are also noticeably smaller than those in Half-Life 2, which have bodies approximately the size of a watermelon. The description for the plush headcrab collectible item indicates that the six-inch toy is quarter-scale, meaning that a normal-sized headcrab is typically two feet in length.
Half-Life and Half-Life 2 also oppositely depict the headcrab's tolerance to water and toxins: while headcrabs in Half-Life can swim but die in toxic environments, headcrabs in Half-Life 2 drown instantly in deep water but easily survive in contaminated pools. The headcrab's resilience towards toxic and radioactive materials appears to be passed on to their hosts, as zombies are frequently found in conditions that would otherwise be hazardous to their hosts.
The games also establish that while headcrabs are parasites they prey on humans, they are also prey to the creatures of their homeworld. Bullsquids, Vortigaunts, and barnacles will all eat headcrabs (it should be noted that the barnacles will eat whatever they can grab); Vortigaunts can be seen cooking them on several occasions. Even humans will eat headcrabs, though they are apparently not fond of the taste ("they don't taste like crab", a human comments in Half-Life 2: Episode One).
Behavior
By itself, a single standard headcrab is no great threat to the player or anything else. They are relatively slow-moving and their attacks do very little damage. In addition, they can be killed very easily, a single swipe of the player's crowbar or a few bullets being sufficient to dispatch any variant. The headcrab's only advantage is in its ability to leap surprisingly fast over great distances. In flight, it will tilt upwards to face its mouth towards its target, attempting to attach itself to its target in order to control it.
Headcrabs have a penchant for lying in wait in dark corners and ventilation shafts. In more open environments, headcrabs are known to bury themselves in the ground to hide, then climb out to the surface and attack when a victim draws near. Headcrabs are often seen clustered in groups to make up for their individual weakness. They will pursue their prey with single-minded determination, never fleeing despite the death of fellow headcrabs or any other dangers.
Headcrabs can produce a variety of vocalisations. When they are not hunting, headcrabs usually emit squeaks and fairly quiet, repetitive calls while gently swaying their bodies back and forth. When attacking, headcrabs emit a sharp, shrill shriek as they leap towards their victims.
Fast headcrab
The fast headcrab is introduced in Half-Life 2. This version, though similar in color to the standard headcrab, has long, spider-like legs, which allows it to move much faster. It does not have a "beak" like the other varieties, instead using the sharp talons at the ends of its legs to latch to hosts. It is also capable of clinging to walls and ceilings using its talons, an ability first seen in Half-Life 2: Episode One.
Poison headcrab
The poison headcrab (also known as black headcrab and venom headcrab) is also introduced in Half-Life 2, shortly after the fast headcrab. This version is identifiable by its dark sage green color skin (sometimes with a wet shine) and thick hairs on the joints of its inward bending legs. To distinguish it further it has white bands that encircle its knee joints. It also makes a chirp at range and a hissing/rattling similar to that of a rattlesnake's tail when it detects a viable host. Unlike the other headcrabs, the poison headcrab has some survival instinct, as it will retreat when injured.
A poison headcrab will move slowly and cautiously when maneuvering, but like the other headcrabs will quickly leap with an angry squeal when it has a clear line of sight to a potenital host. At walking pace, the poison headcrab is the slowest of the headcrabs, but will run much faster than a normal headcrab if injured. Several poison headcrabs will group together on a single host once one is found; the attacking poison headcrab controls the host while the others use the new host as transportation. Since poison headcrabs are the slowest of the headcrabs, they have adapted by having the host throw them at new hosts.
The most notable aspect of the poison headcrab is its namesake neurotoxin delivered from four fangs on its "mouth": in one attack this neurotoxin will reduce the player's health to one hitpoint, regardless of the current health amount or HEV suit charge. However, assuming the player is not injured further, the HEV suit will provide an antidote, restoring the player to their original health total (one or two points may be deducted) at intervals of ten points every two seconds. The attack also reduces the HEV suit's charge (if any), which is not restored. While this makes it next to impossible for even a large group of poison headcrabs to kill the player, it does make fighting other enemies at the same time (other headcrabs, zombies, Combine, etc.) far more dangerous. According to Half-Life 2: Raising The Bar, the development team noticed that upon hearing the poison headcrab's cries, playtesters would frantically start looking around for the poison headcrab so they could destroy it, regardless of any other present dangers.
Headcrab zombie
A headcrab's primary goal is to attach to the head of a suitable host using its mouth (typically covering the face and most of the head). The headcrab then burrows its claws and hind legs into the host, whereupon it takes control of its victim's body, rendering the unfortunate individual a mindless zombie-like being known as a headcrab zombie, or "necrotic" as the Combine Overwatch calls it.
Once the headcrab is attached, it opens up portions of the skull with its mouth (there is no model showing a headcrab zombie with the entire skullcap missing, so it is assumed that the headcrab does not actually take off the skull covering). By incorporating parts of its biological workings with the motor cortex of the host's brain, it is able to utilize all of the motor functions of the host. However, as evidenced by the screams of the infected host, it appears that the host is actually still alive and aware of its fate.
Interestingly, no Xen species are seen infested with headcrabs. Indeed, the physical makeup of the headcrab, and its apparent need to clamp on the "head" of a humanoid makes it unlikely that it is capable of "zombifying" other creatures of Xen. As such, it is unclear how headcrabs subsist in their native environment, and even more unclear how this ability evolved. Lamarr, Dr. Kleiner's pet headcrab, is fed watermelons, which suggests that headcrabs are omnivores.
Like standard headcrabs, both fast headcrabs and poison headcrabs are also capable of attaching to a host's head, although these headcrabs each induce different forms of mutations on their hosts and the resulting zombies employ different strategies of attack. An unusual characteristic of both zombie variations is that only three middle fingers of the five on each zombie's hands develop into claws, compared to all the fingers on a standard headcrab zombie. In addition, neither two variants have a describable "maw" nor the chest cavity that normal headcrab zombies possess, although fast zombies do have cracked rib cages and seemingly no internal organs, creating a hollow space.
In most cases, a headcrab remains attached to its host until destroyed. In Half-Life 2, however, they have the ability to abandon their host if it is wounded significantly. Removal of the headcrab reveals that the host's face and head has been eaten away by the creature; the degree of such damage on these areas depends on the type of headcrab in control. In Half-Life 2, horrified sounds emanating from headcrab zombies imply that, while wounded to a point which would make loss of headcrab control fatal, the host creature is at least partially aware of its horrific situation. Playing parts of a victim's sound file backwards produces extremely disturbing yells of pain. The cries have been interpreted as "God, help!", "Kill me!", "Why! Why! Why!", "Help me!", and, usually when they are on fire, "Why light me?!" and "I like this!".
Standard headcrab zombie
When a standard headcrab successfully attaches to a host, the host becomes a standard headcrab zombie. The headcrab's alien physiology causes various mutations to rapidly manifest in its host, giving it elongated claws, increased strength, and what appears to be a sharp-toothed "mouth" that bisects the victim's chest cavity from neck to groin. This giant mouth has inspired the nickname "Mawmen". In Half-Life 2, their appearance is slightly different; the "teeth" of the mouth are clearly revealed as protruding ribs: a ripped open chest cavity and no sternum. The official Prima game guide for Half-Life 2 still mentions the "Mawmen" nickname, however. An effect that signals a zombie's presence in the run-down areas of City 17 is the buzz of flies, showing that the corrupted body of the victim is rotting.
The standard headcrab zombie can be detected by the moaning sound it makes when moving, which also suggests that it is in pain. Once it detects a victim, it slowly and purposefully edges its way towards them, using its claws and enhanced strength to beat them to death. Because headcrab zombies are slow, they are often found in confined spaces and/or in large numbers to compensate. In addition, standard headcrab zombies will often feign death until the player approaches, catching them off-guard. The zombies appear to retain very little of their former intelligence and blindly pursue prey, oblivious to other dangers. This makes them especially vulnerable to traps, and the town of Ravenholm in Half-Life 2 is primed with fire and crushing traps to capitalize on this. In Half-Life 2, they can swat loose objects on the ground when they run into them, creating potentially lethal projectiles. Some of the zombies encountered in the game have no body below their waists; they crawl around with their arms and swing at the player. Ironically, though slower, these half-zombies are harder to approach.
The gonome is apparently the next step of a standard headcrab zombie's mutation. It is larger, stronger, and more intelligent than "ordinary" zombies; it also produces a volatile saliva (similar to that of a bullsquid) that the creature can retrieve from its chest "maw" and throw as a weapon. Gonomes can create lairs, or "nests", for themselves with enough time. Gonomes appear only in the expansion pack Half-Life: Opposing Force.
Fast headcrab zombie
When a fast headcrab attaches to a host, it produces a fast headcrab zombies. These zombies are stripped of their outer skin, some body tissue, and most or all organs, leaving large parts of the victim's skeleton exposed. They retain the elongated claws like the normal headcrab zombies. As the name suggests, the fast headcrab zombie is, like the headcrab that spawned it, much faster than the normal variant. It can not only run, but can also jump great distances and rapidly climb walls, despite the absence of most of their muscle tissue. They also move on all four limbs, but stand on two legs when attacking a victim.
Fast zombies, if not visually detected well in advance when leaping across buildings, betray their presence with the ear-piercing howl they let out. They also scream when they are about to attack. A fast headcrab zombie's usual method of attacking, when given a clear distance between it and its prey, is to leap forward several yards in an attempt to tackle and claw its prey into the ground. Though they are not as numerous as standard zombies, they often attack in groups of two to three. Like the standard zombies, the crawling upper torso of a fast zombie is found in Episode Two. Even in this state, they are still much faster than a walking standard zombie.
Poison headcrab zombie
Poison headcrabs produce the poison headcrab zombie, a bloated, reddish/purplish, slow-moving, and hunched-over "carrier" for other poison headcrabs. It is the strongest and most resilient form of headcrab zombie in terms of damage capability and overall health. It is not known how poison zombies are created, as poison headcrabs do not seem to attach themselves to hosts, instead merely injecting poison into their victims. It should also be noted that when (or after) killing the poison zombie in Half Life 2, the host is missing most of the skin on its back thereby revealing its spine.
A poison zombie reveals its presence with its distinctive strangled heavy breathing and muffled moans. Despite being created from a poison headcrab, poison zombies cannot poison others, though the poison headcrabs it carries certainly can; the poison headcrab zombie, like other zombies, attacks with its claws. Though the poison zombie can do great damage if the player approaches it, its most dangerous weapon is the extra poison headcrabs it carries. The poison zombie can grab the poison headcrabs on its back and hurl them great distances. Furthermore, poison headcrabs hurled in such a manner are always in attack position, guaranteeing that the player will be poisoned if they connect. The poison headcrabs can also jump off by themselves if the player approaches.
Zombine
Half-Life 2: Episode One introduces headcrab zombies created from transhuman Combine soldier. Alyx Vance coins the term "Zombine" for them as a portmanteau of "Zombie" and "Combine". Only Zombines controlled by normal headcrabs appear in Episode One and Episode Two. The introduction of the Zombine enemy was meant to show that, in the wake of the devastation caused by the player in Half-Life 2, what was once a valuable weapon in the Combine arsenal is now just as dangerous to them as humans.[1]
In terms of physical characteristics, a Zombine is more or less built the same as a standard headcrab zombie. The differences lie in what the victim was wearing at the time: the body armor of the Combine soldier still covers the Zombine's body, hiding the chest mouth and making them harder to kill. While incapable of using weapons, a Zombine retains enough intelligence to arm a grenade; however, they lack the intelligence to throw it, ensuring that, barring player intervention, a grenade-carrying Zombine will be dead moments later, often taking several other zombies or the player with it. Removal of a Zombine's headcrab reveals that, aside from the lower jaw and small lower portion of skull, no head or helmet remains on the soldier's corpse. The official Prima strategy guide for Episode One indicates that the lack of a head is meant to be an intentional mystery. The Zombines also manifest at least partial awareness of their state, much like regular Zombies. This is evidenced by its "speech", which is composed of Zombie growls and Combine soldier reports, such as "Necrotics inbound" or "Sector's not secure."
Zombines, like regular zombies, groan constantly, which are filtered through the soldier's vocoder (this occurs despite the fact that the Zombine has a total lack of skull and mask, presumably because the voicebox is implanted in the neck). Zombines move faster than normal headcrab zombies (capable of short sprints), but slower than the fast variety. They do more damage than their normal counterparts and are more resilient as well, owing to their genetic enhancements and armor. Aside from their regular attack, Zombines will occasionally pull out a grenade, turning them into potent if brief walking bombs. Zombines often opt to chase the player upon producing the grenade, making them all the more likely to cause damage with it. The player can use the gravity gun to pull the grenade out of the Zombine's hand and punt it away, thereby negating the danger.
Lamarr
Introduced in Half-Life 2, Lamarr is the domesticated headcrab belonging to Doctor Isaac Kleiner. Having been debeaked, thereby eliminating her ability to attach to and control a host, Lamarr has been rendered into a semi-tame pet for Kleiner and a nuisance to anyone else she comes into contact with. Kleiner states that "the worst she might do is attempt to couple with your head…fruitlessly," behavior that leads Barney Calhoun to dub her "freakin' head-humper." Lamarr is named after the late 1930s actress and inventor Hedy Lamarr, as evidenced when Dr. Kleiner alternatively calls her "Hedy" in the conclusion of the chapter "Entanglement".
Lamarr serves as the catalyst for the first few chapters of the single player campaign is in Half-Life 2. When Gordon Freeman attempts to use Kleiner's teleporter, Lamarr jumps from a vent and damages it while Gordon's teleport is in progress, forcing Gordon to proceed on foot once the malfunction subsides. When Alyx and Gordon return to the lab some time later, Alyx has to stay behind to help Kleiner catch her, as Kleiner refuses to leave without her. Lamarr makes her final appearance in Half-Life 2 after the credits, dropping down into a black background and then leaping towards the screen as part of a stinger sequence. Lamarr is safe and sound in Episode One, where she makes a brief cameo appearance, causing further mischief to Dr. Kleiner during his live and unedited evacuation broadcast in City 17. She makes yet another appearance in Episode Two, where the player can see her climb into Dr. Magnusson's rocket, which is launched shortly before the end of the game. Later conversation about the launch implies that Lamarr went up with the rocket.
Use as biological weapons
While headcrabs are merely wild parasites in Half-Life, Half-Life 2 shows that the Earth-occupying Combine alien race have put them to use as an unstable but effective biological weapon against the human Resistance. By storing several headcrabs into "Headcrab shells", man-sized projectiles fired from a mortar-like launcher (only one is featured, in Half-Life 2: Lost Coast, but there would presumably be more for such a weapons system to be effective), the Combine can bombard distant areas with them. The payload of each shell is released into the open shortly after impact, free to infest or kill nearby victims without risk to the Combine forces. As the devastated town of Ravenholm demonstrates, repeated bombings can neutralize entire towns. headcrab shells commonly carry standard headcrabs and fast headcrabs, while poison headcrabs have only been seen emerging from unlaunched headcrab shells during Lost Coast and in the chapter Exit 17 of Half-Life 2: Episode One.
The Combine's mechanism for obtaining large numbers of headcrabs for use in these shells was revealed in Half-Life 2's 2003 code leak, in which a model of an amputated Gonarch sac could be found suspended in a Combine-built frame.[1] Officially, however, no reason has been given.
Merchandise
In order to fulfill their fans' demand for headcrabs, Valve released a plush headcrab for sale at the Valve Store. It featured posable limbs, a number of teeth and claws and a gaping maw. The headcrab went out of sale within a few months. For a 2006 Christmas special, along with the re-release of the plush headcrab, fans can buy a headcrab hat, specially designed to give the impression that the wearer is under attack from the parasitic alien.
Similarities to other fictional creatures
The headcrab is vaguely similar to the facehugger in the Alien movies, although their purposes for their hosts are different. The brainsucker aliens of X-Com: Apocalypse. Brainsuckers are small four-legged yellow creatures that leap onto a victim's head, though brainsuckers fall off and die following a successful zombification. The Flood parasite from the Halo video game series are also similar to headcrabs. Remotely similar to the headcrabs, the Flood parasites send needle-like tentacles into the victim's neck to control the victim via the spinal column, though they are filled with flammable gas and explode violently when killed. They also turn their victims into zombies, although they act more intelligently, using firearms and vehicles. They too, have many different forms as of Halo 3. Though the first Halo game was released after Half-life, the conceptual genesis of the Flood actually pre-dates Half-life with Bungie's earlier game Marathon 2: Durandal as can be seen in some of the concept art for that game.[2] The headcrab's parasitic ability is also speculated to be inspired by the capability of the Emerald Cockroach Wasp to paralyze and control "zombie" cockroaches, in a manner that could be similar to how a headcrab controls its host [2].
Similar plot devices are used though fiction such as in Ian Livingstone's fighting fantasy book Island of the Lizard King, involving a creature called a "Gonchong" whose proboscis would burrow into the head of a host to control it, Clark Ashton Smith's short story The Vaults of Yoh-Vombis features slug-like creatures that eat away human skulls, then control their victims through neural stimulus; unlike the Gonchong, the headcrab does not actually bury into the skull of the host. In the Star Trek film The Wrath of Khan, Ceti eels are used. In all these examples an animal is used to control the thought and or actions of a human host.
References
- ^ Half-Life 2: Episode One, Chapter III: Lowlife, Developers commentary [2006]
- ^ "Marathon Series Concept Art" (HTML and JPEG). Concept art by Robert McLees. Retrieved 2007-11-09.