Underworld Creature

Underworld Creatures are an alien species hailing from an unknown world, but ended up on Earth. By then, many people either have deified them or demonized them, referring to them as Vampires.

Biology
The vampires are not born this way, but rather infected with an alien parasite, which will infect virtually any kind of host organism, regardless of their size or abilities. The parasite will enter the body via through being infected by others carrying the parasite, usually mouth to mouth. Once inside the body, it will lead to the death of their host, then reanimating it. The host typically will be controlled by the parasite in order to infect more uninfected individuals.

Hosts infected with the parasite, typically grow Nosferatu-like fangs, which consist of the two front top teeth becoming much longer, their eyes becoming milky white. They feed upon the adrenaline within the blood of living creatures, regardless of their origin and can do this for virtually any lifeform. Regardless of the species infected, these vampires are capable of living for centuries unless killed.

Alien Vampires
The alien variant of vampire, are 8 ft tall, bipedal, possessing bat-like wings, two of which are fused to their arms and 2 smaller wings on the bottom half of their body, which enable them to fly. This variant is blind, using echolocation as a means of visualizing the environment around them, particularly via clicking. They are also highly durable, with bullets from normal small arms do little effect to damage them, but a weapon like a Vickers machine gun was able to slow them down to a degree. Heavy objects are able to stun the creatures, but not kill them, such as being crushed under a truck. These aliens are capable of cocooning themselves and preserve their body via an alien fluid, which keeps their bodies from aging. This fluid is also excellent to preserve humans, regardless whether or not they are infected. The hands and feet on the beasts are sharp, easily capable of injuring or killing a human. They also are extremely agile, as well as strong, possessing powerful hearing. These also possess several tentacle-like spikes which protrude out their backs.

Human Vampires
Much like the alien variant, human vampires are infected with the same parasite. They possess all of the same characteristics as their alien counterparts, but possess normal vision, but with milky white colored eyes. They possess the same fangs like their alien counterparts, possessing a higher degree of physical strength and speed than normal humans. Their abilities however are not on par with that of their alien counterparts. They also possess small tentacle-like spikes which protrude from their body, which are aspects of the parasite.

Weaknesses
Probably the most common weak spot of these beasts, regardless of the species they infect, these vampires are highly sensitive to ultraviolet light, whether it be natural or artificial. Exposure to ultraviolet light will cause them to ignite, dying of their exposure, should they find themselves unable to find darkness. Their sensitivity to light is so bad, they are even hurt by the moonlight. Alien Vampires are capable of this, but it's highly unknown if Human Vampires are vulnerable to the same degree as their alien counterparts, but it's highly possible. Human Vampires, when exposed to such light, typically look away from the light.

Decapitation or any kind of brain trauma is also ideal for slaying these vampires, as well as staking them through the chest. Since the hosts are in a sense dead, once the host and the parasite dies, the body will decompose rapidly. Fire and any kind of extreme heat is ideal for inflicting damage onto them, whether it be torch or even flare.

History
The aliens that would become vampires, would end up crash landing on Earth, millions of years prior to any other civilization rose. Those who survived, were infected by the alien parasites aboard their vessel, which turned them into blood sucking creatures. By 2231 B.C, these beings were both deified and demonized by civilizations all over the world, particularly in Sumerian myth, as the basis for the demon Pazuzu. Following the deaths and turning of either Balathu or Kurum, the vampires remained undisturbed for the next several millennia. Shepards would find their flock had been attacked by vampires throughout the 19th and 20th centuries, suspecting a pack of wild dogs responsible, but only heard the sounds of clicking on moonless nights rather than barking. Several others went missing during this time, where it was said that their organs were sacrificed to the vampires.

From 1946-1947, an expedition was led by British archaeologist Dr. Randolph Hodgson, who had recently married and would have to spend their honeymoon in the Middle East. They found what they believed was a tomb, but in actuality was a Sumerian temple, as well as the ship beneath it. Investigating the vessel however, caused the vampires to reawaken and attack the team, infecting Randolph's new bride and her turning in a few days. The only one uninfected was Randolph himself, who died by self-inflicted head wound to ensure he didn't die by those creatures and become one himself. It would 56 years before the temple and ship were uncovered. By 2003, Eric King with the use of his Caelus software, found the site, believeing it to be a silo, causing him and a team of several others, including his estranged wife Rachel to investigate. Following their arrival, they ended up ambushed by Iraqi forces, leading to the two teams falling into the temple below.

They attempted to continue their conflict, only to be attacked by the vampires. Most of the Iraqi forces, with the exception of Lt. Salim Othman and several US members were slain and with little choice, worked together to brave the temple, as well as discovering the ship beneath, as well as learn more about what they were up against. They even destroyed several cocoons prior to their ascension back to the surface, however before they could be evacuated, a solar eclipse occured, giving the vampires a 6 minute window to attack them again. They surrounded the remaining survivors in a nearby house, where they survivors held them off until the eclipse ended, causing the vampires to ignite in flame, either dying from their exposure or by going back down into the massive hole the survivors escaped from prior.

Appearances

 * The Dark Pictures: House of Ashes