Standard Headcrab

"Fascinating...these 'crabs' could completely control their host's nervous system."

- Black Mesa Scientist

The Standard Headcrab is the most common Headcrab subspecies, first introduced in Half-Life.

Overview


Headcrabs are fairly small creatures, about two feet long from front leg to back and a foot wide. They have round, smooth, flesh-colored bodies and four legs, two long clawed ones on the front and two thick, stubby ones in the back. Despite their small size, the headcrab's back legs can support its entire body, allow it to "tip-toe" across the ground and leap several feet into the air at its prey. Four "mouthparts" can be seen on their front that end in sharp fangs, possibly used to either hang onto a host or possibly inject them with a sedative or some other chemical. Under the body is a round, lipless mouth containing a sharp "beak" used to burrow through the host's skull. (Dr. Kleiner refers to his pet Headcrab Lamarr as having been "debeaked", hence the term).

Headcrabs can produce a variety of vocalizations. 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.

In Half-Life, Headcrabs are found to have originated from a giant creature known as a Gonarch which shares similar physical qualities with Headcrabs. Underdeveloped "baby" Headcrabs spawn at a rapid rate from a sac that dangles beneath the creature. Baby headcrabs look similar to baby scorpions, very tiny creatures with soft, translucent white bodies.

Behavior and skills
Although small, slow-moving, relatively weak on its own, and even seemingly harmless with its tip-toe like gait, the Headcrab has the ability to quickly leap long distances using its hind legs, while tilting upwards to face its mouth towards its target, inflicting minor injury with its claws, legs, and teeth. Its main goal, however, is to attach itself onto an appropriate host's head. Once attached, they take control of the host's nervous system and dreadful "mutations" occur, creating a Headcrab Zombie.

A Headcrab will frequently lie and wait in dark corners or ventilation shafts for unsuspecting prey to walk by. In more open environments, the creatures are known to bury themselves in the ground to hide, then climb out to the surface and attack when a possible host draws near. Headcrabs appear to be fairly unintelligent creatures and will pursue their prey under the most dangerous conditions, moving through dangerous areas or towards hostile prey, even as fellow Headcrabs die in front of them.

Headcrabs have been observed to be prey for Bullsquids, Vortigaunts, and Barnacles, though Lamarr seems to have a taste for watermelons, suggesting that Headcrabs are actually omnivorous, or possibly scavengers when not looking for a host. Headcrabs have also been seen cooked and prepared in different dishes by Vortigaunt chefs in Black Mesa East, which suggest that they are used as a common food source after the extinction of most of earth's species. Citizens in Half-Life 2: Episode One comment that "They don't taste like crab."

It is also apparently possible to "tame" a Headcrab to some extent, as demonstrated by Isaac Kleiner's pet Headcrab, Lamarr.

Tactics
Standard Headcrabs do not pose much of a threat on their own. They are easily taken out and their bite does little damage. With other kinds of Headcrabs, though, they can be deeply irritating. Focusing on more dangerous enemies, the standard Headcrabs can leap at the player while they are distracted. The best advice is to keep moving at all times when facing the Headcrabs and zombies. If a standard Headcrab is leaping, the crowbar will kill it instantly in one swing. It is also fairly simple to hit the Headcrab with Gravity Gun bursts.

The main threat that Headcrabs pose is their numbers. It is common to find 12 or more standard Headcrabs, often mixed in with other types of Headcrabs. In a case involving Poison Headcrabs, The Poison Headcrabs should be killed first, as their bite will drain a player's health to 1, leaving the player extremely vulnerable. In smaller groups, the Magnum is ideal against Headcrabs. In large groups, or when mixed with other types of Headcrabs, a weapon with a larger clip is a better choice.

Behind the scenes

 * The Headcrab was originally to be used as a weapon in Half-Life 2, mirroring the Snark from Half-Life, as part of the Brickbat weapon. This weapons was to include other props that could be picked up and thrown on enemies by the player (spawning the Molotov cocktail in the playable Half-Life 2 Beta will show Freeman holding a Headcrab, while it appears as a regular Molotov when thrown).


 * The Alien Assassin cut from Half-Life 2 was also to have its own zombie version.


 * Headcrabs are very similar to Xenomorph facehuggers. Both appear as small creatures that attach themselves to their victims' heads. They also share the same skin color and make similar vocalizations.

List of appearances

 * Half-Life: Day One
 * Half-Life
 * Half-Life: Uplink
 * Half-Life: Opposing Force
 * Half-Life: Blue Shift
 * Half-Life: Decay
 * Half-Life 2
 * Half-Life 2: Raising the Bar
 * Half-Life 2: Episode One
 * Source Particle Benchmark
 * Half-Life 2: Episode Two