Biological Reactions to Xenoform Invasion (You guessed it... A Headcrab thread.)

[SilentGunz]

Headcrabs are like ants because they have a queen (Big Momma). Or maybe they're like bees, where the headcrab that gets fed the most royal jelly (or maybe brains) mutates to a queen.

And I think that the headcrabs have to be able to take over vortigaunts, otherwise their ancestors would not have evolved to headcrabs (there were no humans until Black Mesa)

 

[Pesmerga]

2. that zombie sitting on the chair was stunned by electricity !

Uhh, wrong. It was playing counter-stike.

 

[Dracarys]

I like the maturing idea: A normal headcrab grabs a host, and the headcrab is provided from that host with enough energy to grow/modify itself, along with the host. Poison zombies might be what happens when multiple headcrabs try to take the same host; in xen, they might have evolved to not fight over it but cooperate to take more hosts, thereby further propogating the species. Someone else can work out the details

 

[Sid Burn]

Hmm... I wonder wat the headcrabs do back in Xen... were no human host to land on...

 

[SilentGunz]

They probably feed on vortigaunts... not as tasty though, lol

 

[Spoit]

Why couldn't the abundance of regular headcrabs despite being less competitve than the other types be explained by the combine launching them at areas, while the other species presumably aren't replenished (as an earlier poster said, all the combine missles we see had regular headcrabs)

 

[Great Grizzly]

i think they are like ants. one headcrab becomes fertile and makes more head crabs. Once the headcrabs reach a certian age, they go out to look for food for the hive. To do this, they use larger species,(humans,vorts) to capture, and kill and bring food back to the queen (they dont necisarally eat their host, that would be counter productive). Then another fertile crab is born(probobly every 1:20) and it travels away from the hive, grabs a host, (for food and protection) and starts making more crabs.

They use the stomach of the humans to store the food, to take it back to the queen and the hive.

THe crabs attach to the head and empties a fluid (the same fluid the poison crab makes) into the back of the spine, blocking the brain from sending messages to the tissues in the rest of the body. They then can control the body tissues, and thus can move were they want. these fluids also causes the hosts to mutate. This probobly doesnt happen when crabs take over xen creatures, the crabs just use them and dump em, no mutation. Humans however, are so alien, that the bodies react to the toxins, in very strange ways.

The poison (the poision stinger is on the front, so they can inject you with out covering your head, alot more efficient then fightng with the victim for control of the head) and the fast crabs are genetically made by the combine. There are some fast crabs that come out of the shells.

 

[Pax Ethenica]

Deviation in the Base Strain

Now then, I've speculated quite a bit upon the generic strain of Headcrab, and gone into gorey detail into the generic zombie and how it is formed. Now, I'm going to go into theorhetical again and put forth ideas on the new strains of Headcrab.

First of all, the new strains cannot possibly be different Xen-originated species, simply because these divergent strains all seem to follow the basic body plan as far as ingestion is concerned. This suggests that they would feed upon the same animals or plants, or plantlike animals or what have you to survive... Competition would arrise, and a successful species would never have gone about if they dind't know to eliminate the competition. There is, however, no animosity between the three breeds of Headcrab, so it is more than likely, that these new strains are based upon the origional strain, and that while there are gross physiological mutations between them, that upon either a pheromonal or possibly even an electromagnetic (We still have no idea what other senses headcrabs might have beyond a sense of smell... With no eyes, how could they know to jump on your head?) level that these three strains are the same.
But! "How could they develope such gross dismorphisms in just a few years according to the timeline of the game between the origional portal storms the time we enter Ravenholme?" Well, if you think back to my previous post regarding a possible mutagenic 'puss' pumped post-mortem into a victim... Now, this stuff has to be very powerful in its effecasy(SP?) and thus very dangerous even to the headcrab, otherwise it'd take weeks to mutate and zombie and by then the body would have decomposed beyond usefulness. You also have to keep in mind that perhaps not all headcrabs who are shot at were killed. They can, indeed, take more than one gunshot to thier center of mass and come away from it lunging at your face. So, I propose this little thought:

Headcrab A, a normal everyday headcrab fresh from Xen. Suddenly finding itself in a completely alien environment, goes from it's happy-go-lucky self, into a nervous, fidgety killing machine out to meld and sybiose itself to something it can wrap its maw around.

Human B, a soldier, scientist, or cop form Black Mesa... Or perhaps some peasant, it doens't matter. What does, is that this human is marignaly armed, or not very good with his/her weapon. Lets say they were taken by surprise by a vortigaunt from behind, or they just had a close call with a Bullsquid or Antloin. Either way, they are seriously wounded and in no condition to fend off another surprise.

Headcrab A attacks Human B, Human B injured Headcrab A, but is taken by Headcrab A despite his/her best efforts. LEts, for the sake of arguement, say that Headcrab A has been shot through its body by a bullet. Its internal organs have suffered a casade of ruptures in a linear direction through the fatty hindquarters of its body. A fatty something, prolly a gland for mutagen, spills into the creature's bloodstream. Headcrab A being a nonsapient entity doesn't really care, it'll prolly patch up when its done absorbing its foreign but edible and unwilling host.
Headcrab A finishes its meal and gains a good 70-80kilos or so. It begins gestating; having suffered mutations itself while it was a zombie, and whats more its eggs have suffered a similar fate by the ripped open mutagenic gland or sac being ruptured. This batch of eggs holds a pandora's box of unpleasant surprises, an amalgam of headcrab, human, and mutagenic mixer inside each chewwy embryo.
Big bad momma Headcrab A moves along, or gets killed by a passing Overwatch patrol or Strider stomp (ewww... squish), leaving its eggs to hatch upon thier own. A nest of freaks is born, some are spindly and fast, others are hairy, others are hairy and poisonous, some are less as hairy and poisonous and the majority of them are incapable of reproduction or die soon after because they have no legs or mouths or internal pores for expelling waste and they die poisoning themselves... Needless to say, it's something you don't want to walk in on unless you have a good grenade-ladden SMG with you.
Some of these freak-strains live on in different parts of the world, and doubtless other Headcrab A's have similar experiences on different continents, (In HL1 and HL2, you don't exactely span the globe in your adventures.), but most of these new strains die out because of competition without the ability to outdo the generalist design of the origional headcrab, or simply because they aren't viable physiologically.

 

[cabbs]

I personally believe that the different headcrab strains evolved in much the same way as creatures here on earth have.

Now, i dont have a familiar knowledge of how teleport works, or where xen is, but lets assume that Xen exists on a parralel universe and inhabits the same space as our own planet. The portal storms were the teleportation of creatures from their location in xen, directly to the corresponding location on earth.

In Black Mesa (america) we only see standard headcrabs, but in City 17/ravenholme (eastern europe/western russia) we see all strains we know of. In the same way that species vary across continents on earth, they must also on Xen. For this reason, we only see the diff. strains in hl2 locations.

When we visited Xen in hl1, it is mostly vast void with occasional rocks, so how did headcrabs get around? The 'new' strains seem central to one location, but the standard strain is every bloody where. We know that the combine took Xen, and that they use the standard strain as a weapon, so we could assume that they used the same headcrab tactic in Xen (but more often, there were no shortage of heddys when they got there), thus spreading the strain every where, including places that are already the habitat of the different strains.