Alien Species

Sil's Species are an unnamed, sexually aggressive alien species intent on spreading itself throughout the universe by infiltrating, breeding with, and annihilating the intelligent populations of other planets. It is capable of rapid growth and can bond its own DNA to that of other creatures through copulation, reproduction and other forms of genetic contact.


Professor Herman Cromwell claims that the original species originated in the Large Magellanic Cloud (called the Magellanic Galaxy), the only other place in the universe where carbon-based life had apparently been discovered. It is also stipulated that they were a "cancerous" race that visited Mars millions of years ago when its surface was similar to that of Earth, and annihilated all life on its surface before leaving remnants of their DNA in its soil.

Mankind's first interaction with this particular species occurred in 1994 when the SETI (Search for Extra-Terrestrial Life) project received a pair of messages from outer space. The first message contained a more efficient use of methane, while the second contained a DNA sequence along with directions on how to mix it with human DNA. As the first message was seen as friendly contact, scientists went ahead and performed the fusion. Three living organisms were created, two of which were put into frozen stasis in liquid nitrogen, while the third (a female) was allowed to grow under the code-name "Sil". Sil was later succeeded by several more generations of the species.

Racial Characteristics & Abilities[]

The Species basically appear to be bipedal (humanoid) forms with the exception of Patrick Ross, a male of the species. Patrick Ross seems to have two types of alien forms: bipedal and quadrupedal. Both genders of the Species have chitinous, skeletal bodies which are semi-transparent. The mouth has two mandibles and they possess hair-like tentacles. 

Sara's transformation

The species also has the ability to shape shift between human and alien forms, as well as a limited ability to morph their alien forms for the purpose of adaptation to given situations. The DNA structure of the species is extremely versatile and is constantly evolving and mutating which in turn gives them incredible regeneration abilities that render them immortal in the fact that they can only be killed by having every last bit of their body destroyed.

Most of the members of the Species seen are actually mutations from humans. However, a pure form as been seen, taking the appearance of a blobby, tentacled monster with a long mouth-like appendage that lashed out at whatever was nearby. The alien grew so fast that it would double in size in a matter of seconds. After a little over two minutes of life, it was killed by immolation. A similar creature is born from a female human astronaut infected by the alien DNA. The purest of the aliens seen was Sara, due to the fact that she was the daughter of the late Patrick Ross and the Sil duplicate Eve.


The female of the Species is the most prominent as well as decidedly the most dangerous. The movies reveal numerous generations of the female species, each varying in appearance and abilities. It can be assumed that as the species procreates (whether with humans or other hybrids) it evolves and improves with each generation. However each generation share similar physical characteristics.

First Generation: Sil[]


The most prominent hybrid created by the species was "Sil". Fused with high quality human DNA, the alien DNA induced rapid growth, causing Sil to form into a visible fetus in a single day. In less than a month, she grew into a young girl on the verge of puberty. Sil exhibited great speed and strength, but also suffered from terrible nightmares brought on by her alien DNA. She later claimed that the nightmares “Tell me who I am.” Ultimately, the research team decided creating Sil was a mistake and attempted to poison her with cyanide gas. Sil escapes the lab in which she was created and, while on the run, pupates by forming a cocoon of maroon-colored flesh similar in appearance to the pure alien form. She was horrified by this development and the process appears to be very painful. After a few hours, she emerged from her cocoon as a completely naked (it is unknown if her clothes were destroyed by the transformation or she removed them while in her cocoon; if so it is unknown why she did this) fully-grown (and consequently very attractive) woman.

While still somewhat shy and uneasy, Sil is able to quickly adapt to her surroundings, showing an incredible cunning as she blends into society. Sil also demonstrated an incredible ability to assimilate knowledge just by touch. For example, in a few seconds she has the ability to assimilate entire books simply by touch. How this phenomenon works is never explained. Besides speeding up her growth rate, augmenting her intellect/memory retention, and enhancing her physical abilities, the alien DNA also greatly enhances the most basic of animalistic impulses: the need to procreate. Pretty soon, Sil's alien libido takes over and, in a state of almost constant fertility (she seems to menstruate once), she attempts to mate with human males.

Sil's breast tentacles

Her human form is, in truth, merely a disguise and her true alien form is an exotic, sensual, alien mockery of the human form. Her form is chitinous and reptilian, somewhat reminiscent of the Xenomorphs, but still humanoid in appearance. Her “hair” is a mass of prehensile tentacles which are slicked back behind her head. She possesses two sets of teeth with the internal set being razor sharp. Her breasts, rather than storing fat or mammary glands, instead store long, slimy tentacles which emerge from her "nipples." She can use her breast-tentacles as weapons but they are also used in her amorous mating ritual. Sil has long sharp spines up her back that she can retract and extend at will. These seem to be utilized as a weapon by Eve. Last but not least, Sil's infamous tongue. Her long tongue is tipped with sharp spines and is her primary defense mechanism (or weapon). When threatened, she can simple impale her aggressor with her tongue. This "kiss of death" is shown at least once. Sil's alien form is also capable of holding its breath underwater for an extended period.

Sil giving birth by opening her chest cavity.

Sil eventually seduces and successfully copulates with Arden and she gives birth to a son mere hours later. While she is in labor, her abdomen bulges slightly with her rapidly developing child and her chest begins to separate. At the moment of birth, Sil's rib-cage splits open and separates to reveal her newborn son. Sil's son does not survive for long, however, and is killed minutes after his birth. There remains some conjecture as to how Sil's race conceives and what traits are passed on. Due to the changing nature the species and the diverse variations in subsequent generations, there is no way of knowing for sure.

Second Generation: Eve[]


The Species was recreated again using one of the frozen organisms that Sil originated from. This new life form was given the name Eve. Eve was a clone of the original Sil and was designed to be an "improvement." She was made less aggressive and slightly more docile by making her more "human." While Eve is much gentler than her late sister, her alien mating instincts are still very powerful. This is countered with special drugs to calm her sex drives, along with being completely isolated from the male sex.

Eve is, for the most part, identical to Sil with only a few minor differences. Eve's complexion is more violet while Sil's was a sickly tan. Her head tentacles are longer and hang behind her back more like hair. Eve also seems to have an exceptionally acute ESP ability, being able to telepathically communicate with members of her species. Her breasts, like Sil, also contain tentacles but are only used in her mating ritual. Eve, unlike Sil, does not kill humans.

After a successful mission to Mars, Patrick Ross became infected with traces of the species DNA found on the planet surface. The unknowing astronaut became a ticking time bomb. Upon his return to earth, he and his crew were given a heroes welcome. Patrick later slipped away from the festivities and slept with a debutante and her sister. During the lovemaking session between Patrick and the women, Eve began to sense the breeding of the recently infected human and the gestation of his first child with the first woman, who was in great pain as her womb expanded and the child ripped itself out of her body.

Third Generation: Sara[]


Sara is the daughter of Eve and Patrick. Eve gave birth to her in an ambulance. She was nurtured by Dr. Abbot for research to create a perfect alien DNA. Sara is similar in many points with Sil. But she is less aggressive than Sil and killed the least humans among female species appearing in the Species series

Sara uses her hair-like tentacle

In her alien form, Sara has a more scaly and tubular look than the aliens of the previous movies. She lacks the breast tentacles that Sil and Eve had, but instead she has four sharp "hair" tentacles which she can use to attack. She also has nail tentacles that Sil and Eve didn't have, and reaches it to pick up or attack at long range. Her eyes don't have reptilian pupils but instead they emit a blue glow. Her different appearance may be due to Patrick Ross.

Fourth Generation: Miranda Hollander[]

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Like Sil, Most of the males of this species used tentacle-like tongues. But there are only two known examples of the full grown male of the species, who show alien form and alien abilities except the tentacle-like tongues.

Patrick Ross[]

Patrick Ross

An American astronaut, Patrick Ross, was infected with the alien DNA while on a mission to Mars. When Patrick returned to Earth, the alien DNA that he was infected with soon transformed him into a human-alien hybrid. He then went on a mating spree, impregnating human females who would die shortly afterwards while giving birth.

Patrick mating with Eve

As described above, Patrick is the only known hybrid to have two types of alien forms: bipedal and quadrupedal. The bipedal form is a male version of Sil and Eve's. This form is only seen during the mating scene with Eve. The quadrupedal form is for combat and is more massive and brutish. The reason why he has two types of alien forms is not clear, but one is for sure, he was an infected, not a true hybrid.

Patrick splitting his head

When Patrick attack Dr. Laura Baker, he used a tentacle-like tongue. In quadrupedal form, Patrick demonstrated the ability to split his head in two, thus forming a duel headed form. he used a tentacle-like tongue to kill females by inserting itself into the female's mouth.



Yosef is one of the sons of Patrick Ross. He had an extendable tentacle-penis which attempted to enter Sara's mouth, similar to the tentacle described above. This suggests that the female species in fact can be impregnated via oral intercourse.


It is mentioned that the signal that came to Earth was transmitted through several Black Holes which served to hide its point of origin.[1]

It is unknown what level of technological achievement "The Species" are currently at; however, their mentioned mastery of black holes is a testament to their achievements. It is unknown whether the Species has space travel capabilities, though a space faring vehicle of some kind belonging to the original Alien race is mentioned.[2] It does seem plausible that if the race is advanced enough to manipulate black holes, they would also have achieved advanced space travel.

The species had once established a colony on Mars and consumed all of the planet's natural resources before moving on.[3] It is unknown how they got to Mars and there is no mention of space travel, leaving it open to debate. However, a character speculates that the Species could be literally billions of years old. Their capabilities remain unknown but the human hybrids show an ability to learn and absorb information extremely fast and put that knowledge to practical use.



  • The Species life-form was designed by H.R. Giger, who created the Xenomorphs. Notable similarities between this Species and the Xenomorphs include Patrick's quadrupedal form being massive, brutish, and built for combat.
    • The Species also shares similarities with the Yautja, as they both possess hair-like tentacles and two mandibles near their mouths (though the latter is more in line with the Predalien).


  1. According to the novelization for Species
  2. According to an early version of Species II
  3. According to the novelization for Species II