Headcrabs??

[Obi-Joe]

Where did the headcrabs come from? Did the combine bring them from their homeworld? Or are they a seperate species that came in through the portal that Freeman opened in HL1?

 

[Adabiviak]

Pretty sure they're Xen locals that came through in the portals.

 

[Darkside55]

They're from Xen, but since nothing's originally from Xen, we can assume they're from the Nihilanth's original homeworld and got brought over.

...

You know what just struck me? The Combine were never on Xen, so where'd they get the gonarch sac from that they use to produce headcrabs? It could be as simple as they caught a free-roaming one on Earth, or maybe they can forcibly evolve the headcrabs into gonarchs at an accelerated rate. Another theory would be that the Xenians fled their planet right as the Combine were assaulting, and they captured some gonarchs there. That one's less plausible though, since they probably have no use of unmodified species in their arsenal, and I believe the shells were a human invention.

Just something interesting to think about.

 

[ríomhaire]

They probably got one on Earth.

 

[CrazyJeepDriver]

Well, apparently the Headcrabs main source of food were the Vortigaunts, before the Resonance Cascade, so maybe they migrated as their food source migrated.

 

[ríomhaire]

Er...
1: I doubt that headcrabs have access to teleportation technology
2: They wound up on Earth because of the Portal Storms/

 

[Vegeta897]

1: I doubt that headcrabs have access to teleportation technology

 

[Pesmerga]

 

[99.vikram]

So that's how they became extinct, eh?

 

[Azner]

He means it makes no Sense i think, Gonach probably was on earth and the combine caught it there, and headcrabs were real Xen inhabitants unlike the vortigaunts that were brought there...another theory only