Xenian - Creatures

The Nihilanth
The Nihilanth is believed to have been the single most powerful known inhabitant of Xen and, to date, the only confirmed member of its species. Possessing immense intelligence, powerful psychic abilities and a mastery over dimensional phenomena beyond that of human understanding. The Creature ruled large portions of the Borderworld for an unknown period of time prior to the Black Mesa Incident.
Unlike most Xenian organisms within Xen, the Nihilanth demonstrated the ability to communicate through both speech and telepathic projection. Encounters recorded by Black Mesa personnel described it as highly intelligent and capable of directly influencing the minds of lesser beings. It is widely believed based on the left over data before the explosion of Black Mesa, that the Nihilanth was responsible for maintaining the dimensional breaches that connected Earth to Xen during the Resonance Cascade, allowing Xenian lifeforms to cross over into the human-controlled territories of Earth.
Much of what is known about the Nihilanth originates from fragmented Black Mesa records, the testimony of surviving personnel and the accounts and stories from the many Vortigaunt tribes, some citing accounts attributed to Gordon Freeman himself. As a result, many aspects of history remain subject to debate. What is known however, is that the Nihilanth was not native to Xen, just like various other wildlife of Xen.
According to Vortigaunt accounts, the Nihilanth had fled from the Combine long before Humanity's first contact with the Borderworld. Whether it escaped a conquered world, a destroyed civilization, or an entirely different reality remains unknown. Xen became its refuge; a place beyond the immediate reach of the Combine and one of the few locations it could rebuild its strength.
Over time, the Nihilanth established itself as the dominant power within the Borderworld. Numerous Xenian species fell under its control, either through direct coercion or psychic domination. Among the most notable were the Vortigaunts, who were subjected to centuries of enslavement and forced to serve the Nihilanth's growing domain.
Despite its immense power, the Nihilanth's rule was built upon fear and survival rather than conquest. Evidence suggests that much of its activity within Xen was motivated by a desire to prepare for the eventual return of the Combine. The Borderworld served not only as a refuge, but also as a final line of defence against an enemy the Nihilanth considered too dangerous to take on alone.
To strengthen its position, the Nihilanth gradually constructed a hierarchy of servants and enforcers designed to maintain control over Xen and defend it against future incursions. Among the most notable were the Kingpins, powerful lieutenants believed to have acted as regional rulers and military commanders within the Nihilanth's domain. Vortigaunt accounts describe each as possessing unique abilities and considerable autonomy, leading many researchers to believe they served as extensions of the Nihilanth's authority throughout the Borderworld.
Supporting them were the Controllers, highly mobile aerial organisms capable of projecting concentrated energy attacks and coordinating lesser Xenian forces. Their exact relationship to the Nihilanth remains unclear, though surviving accounts suggest they may have functioned as both battlefield commanders and conduits for the Nihilanth's influence.
The Backbone of the Nihilanth's military power consisted of the Alien Grunts; artificially engineered warriors bred for combat and deployed wherever resistance was encountered. heavily armed and biologically specialized for warfare, they formed the core of the Xenian military presence encounter by Black Mesa personnel during the Borderworld expedition.
Together, these forces allowed the Nihilanth to maintain its dominion over Xen for an unknown period of time while preparing for a conflict it believed was inevitable. 
This uneasy balance ended during the Black Mesa Incident
Following the Resonance Cascade, Black Mesa's Lambda Complex succeeded in opening a stable gateway into Xen. Gordon Freeman was subsequently deployed into the Borderworld where he fought through the Nihilanth's remaining forces and ultimately confronted the creature itself. The death of the Nihilanth marked the collapse of its dominion over Xen. Its armies fragmented, its control over the Vortigaunts was broken and centuries of established order disappeared within the hour. For the Vortigaunts, the event represented liberation. For Xen, it marked the beginning of a period of instability that would eventually be exploited by the Combine.
Whether the Nihilanth was a tyrant, a desperate survivor or the last remnant of a forgotten civilization remains a unknown. What it certain that is death altered the course of both Xenian and Human history forever.
Combine Intelligence:
Recovered Combine archives suggest that the Nihilanth was not a unique creature, but rather the final surviving member of a larger species that once possessed advanced psionic and dimensional capabilities. Little information regarding the species survives; though available records indicate they were considered a significant threat to Combine expansion efforts.
Attempts at assimilation reportedly failed due to physiological incompatibilities and an inability to reliably suppress their psychic abilities. Following repeated incidents of resistance, the species was redesignated for extermination.
By the time the Nihilanth arrived within Xen, Combine records suggest its civilization had already been destroyed. Whether it fled as a ruler, a soldier or simply the last survivor remains unknown.

The Kingpins
The Kingpins - Xen's remaining commanders
During the rule of the Nihilanth, a group of creatures dubbed kingpins were created to act as lieutenants for the rule that the Nihilanth established. Not much is known about them beyond the fact only a few remain- mostly the ones on Earth as the status of their Xenian brothers currently sits as a massive unknown, but can be presumed the Combine wiped them out after taking Xen under their control.
They were creatures of fragmented amalgamations of flesh, designed to be the Nihilanth's successors. But once their ruler had died, the Kingpins were trapped in a power vacuum, failing their original purpose of co-opting the dominion as they sought complete power. They numbered roughly around twelve originally; however, many fell in the initial invasion of Xen by the Combine Empire.
Each Kingpin possessed powerful abilities but each was unique based on their individual ruling style, purpose and overall power they had. While none of them are as strong as a Nihilanth, they are at least considered powerful beings who can manipulate their local space to their desire.
A few abilities are at least common among a few of them, such as the act of teleportation, taking an astral form to project their presence elsewhere; akin to how Vorts use the Vortessence to sometimes allow them to project themselves to another location without physically being in harms way. And of course they could each manifest their own unique and personalized artifact designed to help them control and use their power more efficiently at the cost of a heavy fatigue drain.
Today, only a few known Kingpins are alive adding up to a total of 4 out of 12. These are the four only known to Humanity and the Combine to date:
Tyrant - A deceptive and manipulative Kingpin that rules over one of the largest groups of Xenian creatures on Earth. Instead of using his armies to attack, he generally allows them to stay wild on Earth while he is off to trick the next group of humans, start some oddball cult or even trick Vortigaunts into helping him gain more authority and power.
Despot - Deranged and violent, it chooses to remain in Xen for the time being and only visit Earth on the rare occasion. So far it has managed to out maneuver the Combine and maintains a safe distance- while choosing complete insanity aggression tactics over any strategic moves. Its unpredictability gives it an edge in survival.
Lurker - More distant that other Kingpins and prefers being alone; but certainly likes to keep himself a mystic entity. The lurker generally avoids contact an watches from afar. But it is known they are on Earth with minimal sightings.
Warmaster - Cynical and completely aggressive. Also known to be mostly within Xen and not Earth, it choose to rage guerilla wars with the Combine trying to slow their progression in taking over Xen entirely and using the fragmented landscape to its advantage. Naturally it is a warmonger and not much else is known about its status.
Of course, the dead Kingpins consist of the Grandmaster who was Strategic and wise, the Vanguard brave and courageous, the Patriarch a powerful and zealous one, Aegis durable and stalwart, Ghast venomous and secretive, Voidborn horrific and corrupt, Missionary was honorable and selfless, and finally the Overseer who was efficient and productive in his role.

Aerial Life
Aerial Life of Xen
Xen is home to many species both ground and air. In terms of its aerial species, it has quite a few of both a mix of passive creatures and hostile creatures.
Note: this page is minimal as players will need to research each creature type to know more about them.
Boid [Passive]
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Protozan [Passive]
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Stukabat [Naturally aggressive]
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Controller [Naturally aggressive]
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Sphere [Passive]
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Flocking Floater [Territorial]
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Prrobot [Naturally aggressive]
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Ground Forces
Ground Life of Xen
Xen is home to many species both ground and air. In terms of its ground species, it has quite a few of both a mix of passive creatures and hostile creatures.
Note: this page is minimal as players will need to research each creature type to know more about them.
Headcrabs
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Houndeyes
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Panther Eyes
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Bullsquid
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Chumtoad
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Barnacle
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Crystal Turret
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