I’m thinking it’d be neat if Xen looked like Avatar’s Halleluia Mountains.
Xen will have phallus’s EVERYWHERE
Only because of the flotting islands. Clouds and trees don’t fit in Xen.
What about the trees that bash you?
Those are tentacles.
I mean on Xen, not the tentacles in Blast Pit.
As far as we know, those aren’t trees.
They’re Xen trees, foo.
You don’t touch my posts.
That sounds Great, actually. But someone help me, what is the point of headcrabs? I meen, if their from Xen, and the only thing they turn into zombies is humans, why are they on xen? There’s no humans there? I meen, do they turn vortigaunts, or alien grunts?
Maybe… it was hard to tell what a lot of Xen was trying to look like… giger-esque? maybe… alien plant life? maybe…
Though I admit I’ve not read raising the bar nor do I know of the lore behind Xen, just my personal view of the place had it as an alien natural world.
Fixed those pesky spelling errors 
But there’s still some work on your grammar, I’m giving you some extra homework sonny boy!
Nice. You fixed his spelling errors, but failed to answer his question. 
Y’know Waffle, I’ve wondered the same thing. I think the headcrabs fed on the Xen healing pools until they could latch onto a proper host.
Because we don’t know the answer, Valve hasn’t given a definitive explanation so nobody really knows. We can speculate, but that’s about it
Ahhh, true. 
As far as I know, nothing is native from Xen, so the headcrabs aren’t from Xen as well. But I always wondered about this same thing. Maybe they can control other kinds of creatures as well.
And, if normal headcrabs are born from a normal Gonarch… I wonder what the other kinds of headcrabs are born from.
Perhaps zombification is just as new to the the headcrabs as it is to us. Perhaps what they did to their prey back home was much different.
I believe they’re modified by the Combine.
Except the headcrabs had the zombification ability before the combine discovered humans.