OHNE / OANNEANS

Planet of Origin: Oannes (also known as P3X-866), one of the three moons orbiting a gas giant in the Milky Way galaxy. 30% of the planet's surface is covered by a salty sea and has five major oceans.

The Ohne are a semi-aquatic humanoid species whihc developed a peaceful civilisation on their homeworld. They have a lifespan that lasts 5,000 years and their young reach maturity by the age of 200. Their society is divided into castes; the two primary ones being the Warrior caste and the Scholar caste.

The Ohne homeworld was invaded millenia ago by the Goa'uld  and the Ohnes driven away from their ocean-born cities by bombarding the seas from orbit while slavers waited on the surface to capture the fleeing inhabitants who were transported as slaves to ships in orbit. The Ohnes soon overwhelmed their captors, forcing the Goa'uld to self-destruct their vessel, slaughtering thousands of Ohnes while, on the Ohne homeworld, the Ohnes were launching a counterattack thatquickly routed and the Ohnes retook their world.
The Ohne possess advanced memory manipulation science but do not appear to have developed spacefaring technologies.

Source: Stargate universe, (SG1: "Fire and Water")

NOX

Planet of Origin: Gaia

The Nox are an advanced and peaceful humanoid species, capable of reviving the dead and rendering objects as large as their own city invisible. The Nox are considered to be a member of the "Alliance of Four Great Races", along with the Ancients, Asgard, and Furlings. They are known to be one of the oldest species that inhabit the galaxy though very few know of them. 

Physically, they resemble primitive humans with a faint gray skin color as well as grass-like hair from which branches and leaves grow. The Nox tend to wear primitive clothing with colors that combine gray to gray-blue to violet and scarlet. They appear slightly shorter than average humans with a slight build; they often present an unassuming façade which belies their capabilities. The species are strict vegetarians; getting their nutrition from fruits, vegetables, roots and other natural foods found in the forests of the natural world.

The eldest of the species can reach the age of 500 years with children reaching maturity by the age of 18 years. Once a Nox reaches adulthood, their aging slows down to an almost imperceptible rate. Only during the last two centuries of a Nox's life do they begin to appear old but this also belies their true age.

The Nox are an extremely intelligent and perceptive race that are able to perform complex arithmetic in fractions of a second. They possess an astounding ability to comprehend and retain information with near perfect memories.They make use of the five senses that Humans use but they are far more acute when compared to Humans allowing them to pick up on details and subtleties around them that others would miss entirely. This provides the Nox with abilities that border on extra-sensory perception due to their perceptive nature and heightened senses. In addition to this, the Nox possess the innate ability to tune into the bio-electrical fields within other beings, in a sense "reading" them at a level far beyond normal senses. They are capable of also channeling their natural heightened perception into a number of extraordinary abilities that include the ability to learn languages after hearing them spoken for only a short time, a mild form of mind reading that allows them to detect nearby surface thoughts, and the ability to heal others. With the latter,  the Nox are capable of completely healing the most severe of injuries and even resurrect the recently deceased so long as the tiniest amount of molecular activity as well as bio-electrical energy remains within the body. In order to accomplish this ritual, there is a minimum requirement of three Nox to perform the intense and focused concentration which interrupts their ability to use their technology. They also can render extremely large objects invisible and insubstantial.

 The race has a symbiotic relationship with nature and, in particular, the forests of the world as well as the living beings that occupy it be they animal or plant. In the view of the Nox, all beings contribute to and receive from the universe. This view prevented the Nox from allowing their technological advances to compromise the natural beauty of their environment of their world. Nox scholars long ago discovered that "life", the energy that keeps all beings alive, is in essence a dynamic energy myriad of other energy fields that exist outside the physical form. The Nox believe these external energy fields comprise the "life force" of their planet and the universe itself. In their view, these individual fields, also known as "consciousness" to the people of Earth, exists with an external field with each working with the other one.

The Nox practice philosophy of absolute pacifism and non-violence that is so strict that they refuse even to defend themselves when threatened. Should a Nox find themselves in such a situation, they tend to typically hide through the use of their stealth technology or simply use their technology to remove the aggressors along with their weapons. This policy is so strict that others within their domain are forced to obey their rules of policy of pacifism when necessary. Should visitors attempt to employ violence against one another, the Nox remove their weapons as part of their rules.

The Nox race highly value freedom; both for themselves and for the others. They refuse to infringe the rights of others for free choice except where such individuals choose to make use of violence or war-like ways. As such, the Nox accept no authority except their own and thus refuse to allow others to impose their views on others.

Isolationist and non-interventionist in the extreme, they feel morally obligated to help both sides of an argument, no matter if one side is thoroughly evil.  They will not even fight to protect themselves, however with their ability of rendering objects invisible and resurrecting their dead, fighting is unnecessary.

The Nox  rarely use their advanced technology,  which  includes the ability to create the effect of invisibility, to build floating cities, and to activate the stargate by thought alone. preferring to live in a simpler state with nature. For transport, they seem to mainly rely on Fenri are a large, flying species indigenous creatures that may appear to be hostile to strangerbut mostly keep to themselves.

Source: Stargate Universe. (SG1: "The Nox") (SG1: "The Fifth Race") and Stargate wikia entry.

PLANET BUILDERS / OBELISK BUILDERS

The planet builders are a secretive race of extraordinarily advanced beings able to create an entire star system complete with complex life on its one perfect earth-type planet in a matter of weeks. They makr planets they've made with a 2000 ft tall obelisk structure emitting a feint EM field. While they are in the local group, their sphere of influence does not seem to extend to the Milky Way. (SGU: "Faith")
Source: Stargate Universe  (SGU: "Faith")

ASGARD

Planet of Origin: Unknown, in the galaxy of Ida
The Asgard are diminutive humanoid species which developed a benevolent highly advanced space-faring civilisation governed by a Hihg Council.  They were once part of an alliance of four great races with the Ancients, Nox, and Furlings and visited Earth during antiquity and protected a number of planets in the Milky Way, mianly from the Goa'uld with whom they signed The Protected Planets Treaty is an armistice between the Goa'uld and the Asgard, first referred to specifically in "Fair Game" when Earth is included. The treaty covers 27 planets including Earth,^[6] and ensures that those planets remain free from Goa'uld domination. Other planets in the treaty include Cimmeria,^[1] K'Tau,^[11] PX3-595,^[13] the second planet of the Adara system,^[3] and Galar.^[14] . As of the 20th century, the Asgard are a dying race. Having lost the capacity for sexual reproduction, they perpetuate themselves by transferring their minds into successive cloned bodies, leading to an irreversible degeneration of their genome. They chose to commit mass suicide in the beginning of the 21st century, having arrived at the end of their degenerative cycle, by exploding thri homeworld to prevent that their knowledge fell into the wrong hands.
A renegade faction of Asgard splintered from the others 10,000 years ago over their belief that they should experiment on humans to solve their cloning problems. They traveled to the Pegasus galaxy and continued their experiments, but were forced into hiding after the Wraith defeated the Ancients. 
Amongst the most significant technological advancements of the Asgard are beaming technology, intergalactic hyperdrives, advanced shiled technology and plasma beam weapons. They are very advanced in cloning techniques and have the technology to upload and store consciousnesses and transfer them to new bodies. Neutronium is a key element of Asgard technology. Source: Stargate Universe

ANCIENTS / LANTEANS / ATLANTEANS / ANCESTORS / ALTERANS / ANQUEETAS

Planet of Origin: unknown in another galaxy
The Ancients are an advanced humanoid race who developed an intergalactic civilisation millions ago and eventually ascended to a state of pure energy on a "higher plane" of existence. They are best known as the builders of the Stargates networks found in the Milky Way and Pegasus galaxy.
Millions of years ago, a philosophical division emerged among them. Some grew more and more fervent in their religious belief, while others adopted a more scientific and rational outlook. Ultimately, the two groups split apart and began to oppose each other. The religious ones, aka the Ori, decided to destroy the non-believers who, rather than to fight them, left for what they called Avalon, the Milky Way.
There, they built an impressive empire, a vast network of stargates linking all their colonies and sent ships to spread Stargates to other galaxies. Among the planets they settled was Earth. As the planet's original Stargate in Antarctica was the oldest gate ever encountered, Earth was probably one of their more important worlds and the departure point of their stargate spreading ships. Eventually, they were afflicted with a plague tailored by the Ori. Most fled. Those who remained in the Milky Way galaxy either ascended or died out.
Those who fled to the Pegasus Galaxy settled on a planet they named 'Lantea'. Finding Pegasus devoid of sentient life, they seeded it with humans and Stargates. At some point they encountered a leech-like organism called the 'Iratus bug', which possessed impressive healing and immunological capabilities. Through feeding on humans, this organism absorbed genetic information from them and eventually evolved into the vampire-like Wraith.
The Wraith developed into an advanced but violent hive society while avoiding the attention of the Ancients until they felt their number big enough to confront them. Despite the Ancients' technological superiority, the Wraith overwhelmed them. The Ancients fled back to the Milky Way throught the Antarctica Stargates. Some stayed on Earth, spreading out to distant lands and helping to populate them, Others departed the planet, to live out their days on other worlds and allied themselves with the Nox, the Furlings and the Asgard. The remainder chose isolation in which to meditate and seek enlightenment. This would eventually lead to a spiritual ascension for some.
After their ascension, the ancients continued to oppose their former nemesis, the Ori, who had also reached Enlightenment. Although the two factions were deadlocked in strength, until, in 2007, a superweapon designed by the ancients was used by humans to destroy the Ori.
Source: Stargate TV series

GREYS / VREES / ASGARD / ZETANS / RETICULIANS

There are numerous sighting claims of Gray type aliens.
In the "Dark Skies" TV series, the Grays are presented as a peaceful highly advanced humanoid civilisation capable of space travel, which have been taken over by the Hive, a communal parasitic species, the Hive, which uses their bodies as host for their expansion plans.

In the "X-Files"TV series, they are presented as an transformation, through the use of another humanoid lifeform, either a reptilian humanoid or a human, of the Black oil parasitic (or symbiotic) lifeform. These Gray type aliens can attain man-like sizes and are capable of shape-changing.

In the "Stargate SG-1", they are called the Asgards and are pictured as an highly advanced species opposed to a parasitic species somewhat reminiscent of the Hive, the Goa'uld.

In Babylon 5, they are called Vree and are said to have visited Earth since hte 1940ies. They are known to be distant relatives of another spacies called Streib and both species have a lot fo similarities with yet another one, the Zener, which is known to have been manipulated by an ancient race known as the Shadows.

Greys have also been seen in the Escape from Planet Earth movie and in the Scrameustache comcis series where they are shown to have some psychic abilities, among them, telekynesis.

Typically, Greys are described as being approximately 120 cm (four feet) tall, with grey (sometimes blueish,) skin. Their body is typically described as being elongated, and lacking in muscular definition. Their legs are shorter and jointed differently than one would expect in a human. Their arms often reach down to their knees, and some accounts give them three digits or three digits and a thumb on each hand. They have a bulbous, hairless head supported by a thin neck, which is dominated by large, usually black lidless eyes. They typically have small flat noses or slit-like nostrils on a flat face, small mouths and small earing orifices. Some accounts have Greys wearing tight neutral colored uniform-like jumpsuits. Other reports have them appearing to be naked. In most cases, they dont have determinable gender and have no visible external genitals.
From the abduction account of Barney and Betty Hill in 1965, they are believed to be coming from a planet orbiting the star Zeta Reticuli.
Sources: Popular culture, "The X-Files", "Dark Skies", "Stargate SG-1", "Babylon 5"

Greys from the X-Files

Greys from Dark Skies

Asgards from Stargate

Vree from Babylon 5

Greys from Escape from Planet Earth.

The Small Greys from the Scrameustache