Nihilanth

"Truth, you can never know the truth..."

- The Nihilanth

The Nihilanth is the leader of the Xen forces that invade Earth during the Black Mesa Incident, who also acts as the primary antagonist and final boss of Half-Life.

Overview
Physically, the Nihilanth resembles a gigantic, abnormally proportioned fetus with a massive head atop a smaller body. The creature's minuscule legs appear either to be vestigial or the remains of amputation, as the Nihilanth relies on a mechanical levitation device for movement.

The head is so large that it must be kept upright with a small cord that extends from the base of the spine to the back of the head. The Nihilanth's body features what appears to be the remains of some sort of surgical procedure and, like the other intelligent Xen races, it has a third appendage protruding from the middle of its pectoral chest region, though it is not known what purpose this serves. Its unusually long arms end in huge hands and disproportionate fingers. The Nihilanth wears metallic wristbands similar to bands worn by enslaved Vortigaunts, possibly indicating enslavement, likely by the Combine.

Background
Sometime before the events of Half-Life, the Nihilanth was the ruler of its homeworld, in command of a variety of species, most notably the enslaved Vortigaunts. However, its homeworld was attacked by the Combine, who attempted to enslave the Nihilanth and its minions, leaving it with severe surgical scars and mutilations. The Nihilanth and his minions managed to escape into the borderworld, Xen, where they barely managed to survive in a new ecosystem.

Half-Life
Gordon Freeman is tasked with killing the Nihilanth as it is the only force holding the dimensional rift open after the Satellite Delivery Rocket launched by the Black Mesa Lambda Labs failed to reverse the Resonance Cascade. After Gordon enters Xen, the Nihilanth regularly contacts Gordon telepathically and occasionally taunts him. These messages are often received right after a teleportation in Xen.

Upon entering its lair, the Nihilanth attacks Gordon by launching two different types of energy spheres: a swarm of blue-colored electrical orbs which cause immense damage and a slow-moving, green-colored orb which homes in and teleports him to other sections of the Nihilanth's lair populated by other Xen aliens. In addition, these green spheres also teleport creatures into the Nihilanth's main chamber on impact with the cavern walls to help defend against intruders.

A series of gold-colored "energy spheres" orbit around the Nihilanth's head, rendering it impervious to damage. These are consumed as the Nihilanth attacks or summons assistance, but specialized crystals within the upper portion of its chamber replenish the spheres as they vanish. After Gordon destroyed these crystals, the Nihilanth's head opens up like a flower, revealing a shining, vulnerable brain. After a significant amount of damage is done to this, the Nihilanth floats up to the roof of its chamber and dies in a massive green explosion.

Half-Life: Decay
In Decay, Dr. Richard Keller discovers an alien force actively holding the dimensional rift open from the other side, when Dr. Gina Cross and Dr. Colette Green attempts to release the dampening fields to create a resonance reversal after the Resonance Cascade, leading him to realize that not all the aliens are there by accident. This alien force is more than likely the Nihilanth.

Furthermore, in the bonus chapter Xen Attacks, the Nihilanth orders two vortigaunts, drone subjects X-8973 and R-4913, to retrieve several stolen Xen crystals from the Ordinance Storage Facility in Sector E Biodome Complex, a mission the vortigaunts accomplish. This chapter also shows that the Nihilanth is capable of controlling when/where his minions are teleported, and is capable of sending them quite close to their target.

Half-Life 2
In Half-Life 2, the Nihilanth is mentioned by various vortigaunts throughout the game, such as the All-Knowing Vortigaunt, if they are triggered. It is through these messages that it is revealed that the vortigaunts see Gordon as a messianic figure after he frees the vortigaunts, by killing the Nihilanth at the end of Half-Life. This is also the only in-game instances in the series where the Nihilanth's name is mentioned by the characters.

Quotes


There are several cryptic phrases that are either spoken or telepathically broadcast by the Nihilanth once Gordon Freeman reaches Xen, but most are difficult to understand in-game. Below are transcripts of several speech files extracted directly from the Half-Life sound files, arranged in order of when they are heard. Note that these transcriptions may not be entirely accurate, as the exact contents of the Nihilanth's speech are fairly difficult to make out due to unclear articulation and the low, gravelly manner in which it speaks. Included are comments explaining the most common interpretations of each quote.


 * "Comes... another...": Said when Gordon first enters Xen. This most likely means that Gordon is not the first human to enter Xen, as is also evidenced by the human corpses found throughout the area.


 * "Win... you cannot win...": Said when Gordon enters Gonarch's Lair. The most obvious interpretation would be that this is some sort of taunt to discourage Gordon — this follows from below ("Done.. what have you done...") implying the Gonarch's death was not predicted. It could also be interpreted as the Nihilanth claiming that Gordon will be unable to stop the Combine. Or, it could mean his inability to ever leave the service of the G-man, which would also foreshadow that Gordon would arrive under the G-Man's service as he is not "hired" by the G-Man until moments after this battle.


 * "Done...what have you done...": Said when Gordon enters the chapter "Interloper." This almost definitely refers to the Gonarch and its defeat. As the Gonarch creates Headcrabs, Gordon's interference (perhaps the reason for the name "Interloper") has halted the production of the headcrabs. This could have a major effect since Gordon has fought headcrabs throughout the entire game. Also, the first section of this level is the last time headcrabs will appear, and only a few are seen.


 * "You are man... he is not man... for you he waits... for you...": Said when Gordon enters the second part of "Interloper" at the alien camp. Most interpret this as a reference to the G-Man, who the Nihilanth implies is not human. This seems extremely likely in light of the facts that the G-Man is the only "man" who is portrayed in Half-Life with any significance besides Gordon himself, and that the Nihilanth's saying this predates any plans for either of the game's two expansion packs. It is suspected that the G-Man's employers aren't human, as he said to Adrian Shephard, "...my employers are not so trusting and, rather than continually subjecting you to the irresistible human temptation of telling all..."


 * "Die...you all die...you all die...": Said in the second part of the chapter Interloper. This is most likely spoken in anger; the Nihilanth is probably calling for the death of Freeman, humanity or both.


 * "Alone... aren't you alone... aren't you alone...": Exact phrase as above, but has a different meaning, the Nihilanth is thinking simply that Gordon is surrounded by no one; this is most likely as the Vortigaunt slaves in the first room of the 3rd map of "Interloper", where this is heard, go about their tasks instead of shocking Freeman unless he stays there for a long period of time, at which point one or two slaves will attack.


 * "The last...I am the last...": Said when Freeman enters the final part of "Interloper" near an eerie, coral-like altar with a red portal. It is unknown what is meant by his being "the last." A fan theory suggested that it means he is the last of his species as nothing else like him is seen on Xen - with the possible exception of Alien Controllers (this was later confirmed by Valve). It is interesting to note that at this portal to the game's last battle, the voices of scientists that Gordon has previously encountered throughout the game, including some not even heard at that time, such as the voice of a scientist: "Get him out of there! Shut down the equipment and someone get him out!", can be faintly heard, although hard to hear in-game through the alien sound effect around it, with no proper explanation as to why. Note that the altar looks like a warped version of the Anti-Mass Spectrometer chamber.
 * "FREEEEEMAAAAAANNN!": The Nihilanth screams out Freeman's name at the very beginning of the game's final battle, indicating that it knows Freeman by name. (Assuming that the messages are delivered via telepathy, this is quite credible; such an assumption would also explain how the messages come to be in English, it is assumed this is said rather than telepathically broadcast.)


 * "Alone... not you alone... not you alone...": Unknown. Probably means that other people are "employed" by the G-Man. It could also mean that the G-man is with or simply watching Gordon. Said when the player is teleported by the Nihilanth's teleport orb for the first time. It could also infer that he is not the only one being watched by G-Man and his "employers". It could be possible that all the dead humans around Xen were also being watched for potential employment but observation was terminated when they died.


 * "Deceive you... will deceive you...": This is quite possibly a reference to the G-Man and the way he employs (and uses) Freeman. This may also be a reference to Breen and how he may be preparing Xen for the Combine's swing to Earth. Said when the player is teleported by the Nihilanth's teleport orb for the third time.


 * "Die now...you die now...die now...": Said during the battle with the Nihilanth, when the player is teleported by the Nihilanth's teleport orb for the fourth time. Likely said just to intimidate Gordon.


 * "Their slaves...we are their slaves...we are...": Probably a reference to the Combine, as they enslaved the Vortigaunt species prior to the first Half-Life game.


 * "The truth...you can never know...the truth...": Seems to suggest that the overall plotline will remain filled with unanswered questions.


 * "Thieves...you all are thieves...you all are...": Similarly vague. Possible reference to one of the crystals from the Nihilanth's chamber that was taken back to Earth, along with countless Xen specimens for zoological study. Or it could possibly be that most species want to control Xen to use it for their portal technology (as human teleporters are dependent on Xen; even intra-dimensional Teleportation is achieved by "swinging around" Xen), and they, to the inhabitants of Xen, are stealing it. Also in Decay in the final bonus level when playing as two Vortigaunts, they are sent to retrieve a crystal, or the crystal that started the Resonance Cascade, and bring it back, this supports the theory that the humans were thieves from stealing the crystal(s). (This speech is heard at the beginning of this mission before being ported to Earth, in the same area where Gordon sees Bullsquid feeding.) However, in the Episode Two it is revealed that it is the G-Man who brought the crystal that started the events of the game.

Behind the scenes

 * Half-Life 2: Raising the Bar states that the first part of the Nihilanth's name is reference to nihilism (from the Latin nihil, meaning nothing), while -anth is a common suffix that is related to flowers and is a reference to how his scalp peels open like a blossom.


 * Michael Shapiro is uncredited to the Nihilanth's voice. However it can be verified by listening to the Nihilanth's speech sounds and by changing the speed of its grunting sounds.

Trivia

 * Based on some of its speeches and what appear to be surgical scars and amputated legs similar the that of the Stalker's, it is thought the Nihilanth was once a slave to an obscure higher power, which was later confirmed to be the Combine.
 * Using the high jump objects scattered around the Nihilanth's lair, it is possible to get into its head. Hitting it with the crowbar shows an interesting blood effect not shown anywhere else.
 * It is possible to kill Nihilanth without attacking its brain, simply by shooting it from underneath, although this takes a while.
 * if you use the Invisible cheat code( not to confused Infinite Health) when fighting nihilanth and defeat him. You will get stuck on the level.

List of appearances

 * Half-Life
 * Half-Life 2: Raising the Bar
 * Half-Life: Decay
 * Half-Life 2
 * Half-Life 2: Episode Two