GALMANS / GAMILAS / GAMILONS / ISCANDARIANS

Planet of Origin: Galman, distant of about 20 000 light years from Earth,
The Galmans are a humanoid species looking much like blue skin humans which developed an advanced interstellar technology a long time ago near the Milky Way's core.
At their height, they had expanded throughout the Galaxy and the Magellanic Clouds. However, as the Galman Empire waned, they lost control of their territories and were reduced to a few scant planets near their devastated homeworld. When the Bolar Union rose in power, they overtook Galman space and subjected it to severe living conditions. Of the scattered colonies outside the Milky Way, only the ones estalished on the twin planets of Gamilas / Iscandar managed to survive and prosper.
Circa 2200, Dessler, its leader, saved the Galman from complete destruction by freeing Galman from the grip of the Bolars. The Galman-Gamilas expanded into the Core region, the sagitarius and Orion arms. Their independance war from the Bolar Union resulted in the destruction of more than ten worlds, with the Bolar’s Planet Berth being the first casualty. Both sides used Planet-Destroying Missiles and Warp Missiles. Galman was laid waste by the arrival of the black galaxy phenomenon circa 2205.
Source: Leiji Matsumoto, Leijiverse, Space Battleship Yamato

DINGUILS

The Dinguil civilization originated near the Orion Arm of the Milky Way. They were a philanthropic race that developed interstellar travel.
10 000 years ago, learning that waterworld Aquarius was approaching Earth, they came to conduct a massive rescue effort. The Dinguil saved many people from the flood. However, the humans they brought back with them eventually conquered them and wiped them out.
In 2203, The surviving Dinguil humans tried invade Earth after Aquarius flooded their home but failed.
Source: Leiji Matsumoto, Space Cruiser Yamato

ILLUMIDAS / HUMANOIDES

The Illumidas are an aggressively militaristic humanoid species that developed an interstellar civilisation in the 2900ies, at which time they invaded the Earth. They have a large space fleet and move through space planet by planet, seeking to subdue and exploit other worlds. They are green skinned and only males of the species were ever seen.
They were wiped out by the Arcadians after an attempt to misuse the powere those had betwoed on them.
Source: Leiji Matsumoto, Space Pirate Captain Harlock universe in "Arcadia of my Youth" movie and "Endless Road SSX" TV seies.

STRANGULOUS STILETANS OF JAJAZIKSTACK / JAJAZIKSTCKANS

Planet of Origin: Jajazikstack (now destroyed)
The Strangulous Stilletans were an aggressive sentient species who lived some billions of years ago. They were wiped out by the Silastic Armourfiend of Striterax.
Source: Douglas Adams, The Hithchiker's Guide to the Galaxy

STRENUOUS GARFIGHTERS OF STUG

Planet of Origin: Stug (now destroyed)
The Strenuous Garfighters were an aggressive sentient species who lived some billions of years ago. They were wiped out by the Silastic Armourfiend of Striterax.
Source: Douglas Adams, The Hithchiker's Guide to the Galaxy

ALIEN PICTURE OF THE DAY: ALIEN POKER

TRITOVORES

Tritovores are green-skinned humanoid insectoids with heads resembling those of flies. They communicate by clicking these mouth parts to produce sound and have simple, three-digit hands. They eat the faeces of other species. As of the 21st century, they have developed a peaceful trading space faring civilisation. They have developed telepathic translators allowing easy exchange with other species.
Source: Doctor Who Universe. (DW: Planet of the Dead)

FLOOD

The Flood were a viral species of unknown origin which as been sealed in the martian glacier by the reptilian ice warriors at some point in the past. Under this trapped state, they existed on the planet Mars until 2059.
Flood infects other lifeforms through exposition to liquid. Once a lifeform has been infected, it constantly produces water; the liquid dribbles out of the host's mouth and soaks through their clothes. It can produce further water to break through barriers and locks, and blast high-pressure sprays from their mouths and arms. The infected hosts show parched, cracked mouths, blackened teeth, and, after a while, faded blue eyes. Infection takes place quickly, but the Flood can cover up the physical symptoms for a short period of time.
Flood infecting different individuals maintain telephathic communication and emit high-pitched screams, capable of cracking open ice.
Source: Doctor Who Universe (DW: The Waters of Mars)

SILASTIC ARMOURFIENDS OF STRITERAX / STRITERAXIANS

Planet of Origin: Striterax (now destroyed)
The Silastic Armourfiends were a sentient species who lived some billions of years ago. They were so aggressive that without adversaries, they were could resort to automutilation until they become unconscious. They wrecked the surface of their planet, forcing the surviving population to live in bunkers deep below the surface.
During one of their wars, they asked the great computer Hactar to design them the ultimate weapon. Hactar created a hand-held bomb which would connect the core of every major sun via hyperspace, destroying the entire universe. They attempted to use the bomb to blow up a munitions dump, only to realise that Hactar had built a dud weapon since it could not conceive of an occasion when the use of such a weapon could be justified.
Eventually, after defeating the Strenuous Garfighters of Stug and the Strangulous Stilletans of Jajazikstack, they wiped themselves out.
Source: Douglas Adams, The Hithchiker's Guide to the Galaxy

BANE

Planet of Origin: Bane World (now destroyed)
The Bane are large, beige, vaguely cephalopod-like creatures who developed an aggressive space faring civilisation. They have 7 ambulatory tentacles; 3 on each side and another on their end; a large, single eye on their head and rings of tentacles around their mouths. There are pads on the undersides of their seven tentacles which allow them to walk across ceilings and floors, and a turtle-like shell on the back. They have the ability to read and rewrite memories on others. Born in eggs, they are the spawns of a much larger organism known as the Mother bane. When individual Bane failed, they are eaten alive.
A Bane group that survived the destruction of their world tried and failed to invade Earth in 2008.
Source: Docto Who Universe, (SJA: Invasion of the Bane, (SJA: The Lost Boy)

VEIL

The Veil were a reptilian humanoid species which developed a space faring civilisation. They are known to have conquered several worlds long before humans appeared on Earth. At some point, the Veil homeworld was turned into a ball of ice when their sun was extinguished
They had scaly skin and horns of various size protruding from their head and shoulders. They also had a long tongue which it could flail and retract at will. They had special biological powers that allowed them to hide in the bodies of other beings and stun them as well through simple contact. The veil species has no genetic reference to the Earth's reptiles.
Source: Doctor Who universe. SJA: Prisoner of the Judoon

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