Half-Life Wiki
Half-Life Wiki
This subject is from the Black Mesa Incident era.
Wiki cleanup This article has yet to be cleaned up to a higher standard of quality.
You can help by correcting spelling and grammar, removing factual errors, rewriting sections to ensure they are clear and concise, and moving some elements when appropriate. Visit our Cleanup Project for more details and, please, notify the administrators before removing this template.

The Xen Tree is an alien organism found on the border world Xen and a few locations in Black Mesa in Half-Life: Opposing Force; although it attacks creatures that get too close, it is not known to consume the bodies or do anything to them.


  • They somewhat resemble an upturned root and are around thirteen to sixteen feet tall (3.96 to 4.87 meters tall). A brown-ish tree-like creature with no leaves or branches, they have a fully mobile "trunk", and a large, hook-like appendage at the top, used for attacking nearby prey.
  • These trees are scattered around Xen and can prove a danger to an unwary explorer and other Xen wildlife by violently stabbing at any nearby source of movement, much like a tentacle.
  • Xen Trees attack nearby enemies to kill them.
  • They are often found near Xen's Light Stalk plants, it is a possibility that they are related.
  • Although very hard to accomplish, it is possible for players to trick enemies into walking near Xen Trees. Sometimes, these hostile NPCs can get stuck and the player does not have to exert any effort in eliminating stuck assailants, especially the feared Gargantua.


  • A Gonarch's movement causes nearby Xen Trees to attack even if no prey is close. This suggests that the trees detect their prey using vibrations.
  • Xen Trees are not affected by the console command notarget and will keep attacking even if it is active.
  • If you die from a Xen Tree while touching it, then the Xen Tree will keep firing its stab attack at you indefinitely and the player's view will still be affected by the Xen Tree's hits when he or she is dead. This fact does not apply to Half-Life: Source.
  • Sometimes if you attack a Xen Tree with a Crowbar, Pipe Wrench, or Combat Knife, then the melee will fire much faster than it should like the effect you get once in a while when you try to destroy a corpse with a melee. This fact does not apply to Half-Life: Source.
  • The amount of camera roll from the Xen Tree's hits is greatly increased in Half-Life: Source compared to Half-Life.
  • The HECU RPG's guided laser will sometimes be invisible when pointing at the Xen Tree at certain positions and angles. This does not apply to Half-Life: Source.
  • There are no skill (sk_) commands for the Xen Tree so the skill command does not affect the Xen Tree or the Xen Tree attacking the player at all.
  • The Xen Tree uses an entity called xen_ttrigger to at first know where it can hit a npc or player and know when to start attacking them but in Half-Life: Source, the Xen Tree does not seem to act different once the xen_ttrigger is removed after its initial spawn. The xen_ttriger will spawn at position 0 0 0 if the xen_tree is spawned by the ent_create command.


List of appearances[]

Imagecat The Half-Life Wiki has more images related to Xen Tree.