BULLTON

Found living in two meteorites which crashed on Earth in 1966, Bullton is composed of two small amorphous creatures which, when put one near the other, generate a gigantic centralized mass with several short tentacular limbs arrayed in all directions, many of which ended in orifices from which antennaes can extend which can emit energy whihc warp sapce and time. Bullton's body appears blue , gray and red. On a planet, it moves by rolling over.
Source: Ultraman "Passport ot Infinity"

MEPHILAS SEIJIN

Mephilas Seijin is an advanced species of biped with telepathic abilities which developed space flight. A Mephilas came to Earth in 1966 with projects of conquest. After being thwarted, it left the planet.
The Mephilas that came to Earth could fly, produce lightning bolt from their fingers as well as immobilizing rays, change size and teleport at will. It also had the power to resurrect dead individuals. It remains unknown if those abilities are natural or artificial, ot even representative of the species.

Source: Ultraman episode 33 "The Forbidden World"

ZARAB SEIJIN

Zarab Seijin are a an advanced species which developed space flight. They are 2 meters tall biped but can increase their size about 20 times and can change shape to imitate other lifeforms. It is not known if these abilities are natural or articificial.
Zarab Seijin came to Earth with intentions of conquest in 1966 but were thwarted.
Source: Ultraman

ZETTON SEIJIN

Zetton Seijin are a technologically advanced species of bipeds which developed space flight. They are 2 meters (6.56 feet) tall and weigh 60 kg. With two legs and two arms, they have a large cylindrical head with a with a kind of antenna organ on top of it. They can shapeshift but it is not known if this ability is natural or artifical.
They came to Earth in 1966 and attempted to conquer the planet using a 60 meters tall monster called Zetton. Zetton resembles a giant horned humanoid beetle with a glowing yellow streaky mouth down his face, striped yelloy black limbs and powerful black armor plates on the torso. The yellow panels on his chest are thought to be compound eyes. Where eyes are on most creatures, he has two sensory pits which can emit sonar or radar signals. Where ears would normally be are sensors that acquire the reflected signals. It can shoots 1-trillion-degree-Celsius Fireballs from his mouth, absorb energy waves and rays and recast them from his hands and create a protective force field around him. It is unlikely that Zetton is the product of natural evoluton and is most probably a creation of Zetton Seijin science.
Source: Ultraman TV series

BLASTERS

The Blasters are an aggressive green skined humanoid species reproducing themselves by cloning which seem bent on conquest of other planets. They tried to conquer Earth toward toward the end of the twentieth century but failed.
All blasters look the same and are dressed the same, their only differentication being a numeric identification on their costume over the forehead.

Source : Astroganger TV Series

VOLTRON CONQUERED SPECIES

The Galra have conquered at least two other civilisations of humanoid species that they use as slavelabor. Source: King of the Beasts GoLion / Voltron Lion Force TV series

GALBESTON / DRULES

The Galbeston (also known as the Drules) are an aggressive technologically advanced humanoid species which developed an interplanetary society.
The Drules are physically relatively close to humans but with blue skin and red eyes.
They have developed an oppressive monarchic society.
They may of may not be related to the Galra.

Source: Kikou Kantai Dairugger XV / Voltron: Vehicle Force TV series

GALRA / DRULES

The Galra (also known as the Drules) are an aggressive technologically advanced humanoid species which developed an interplanetary society through invasive expansionnism that originated of planet Galra, also known as Planet Doom.
The Galra are physically relatively close to humans but with pointed ears that enlarge with age. Their eyes are yellow and their skin color can be of all tones of blue. The ruling class seems to be of a median tone of blue while most of the populace seems to be of a darker blue. Children all have lighter tones of blue that darkens as they age.
They have developed a monarchic society based on conquest and slave collecting.
Some Galra are said to use some kind of magic.
They may or may not be related to the Galbeston.


Source: King of the Beasts GoLion / Voltron Lion Force TV series.

LEPONTINES

Lepontines are bovine modified genetically by representatives from an alien civilisation in need of warrior monks to lead their crusade in their place.

Source: Ghislain Barbe & Elie Charest "Earthbound"

EVIL HORDE

The Evil Horde is a spacefaring agressive power bent on conquest lead by a mysterious entity known as Horde Prime.
The few high ranking officers of the Horde, humanoid for the most part, all seem to be unique specimens, with might hint at some artificial origins or manipulations - either genetic or mystic, of the individuals. All are known to have special powers and often use magic. The bulk of the Horde's Power is composed of mass-produced humanoid robots.
Horde Prime and the Horde troopers bear a lot similarities, with the Beast and its army seen in the film Krull.

SNAKE MEN / REPTONS

Snake Men are a species of humanoid saurians who developed as an agressive spacefaring civilisation. They invaded planet Eternia in the distant past and were defeated. There now remains only a handful of them and most of them have devolved into the more peaceful reptons.

ETERNIANS / ETHERIANS

Eternians and etherians are humanoid species ressembling normal humans and genetically compatible with them. It has been hinted that they might be descendants from humans of the future.
They are the dominant lifeform on both Eternia and Etheria, sister planets orbiting a yellow sun whose exact spatial location remains unknown, although it has been hinted that it might be inside a space-time singularity, wether a junction of alternate universes or a pocket dimension caused by the presence, for a long time, of the Starseed at its core, a spark left over from the creation of the universe.
Some kind of wormhole exists linking Eternia's system to the Solar system and two space expedition have been known to fall through it.
Eternia is quite earthlike and has large bodies of water. It is separated into two very distinctive regions, the light and a dark hemisphere.
Eternians developped a technologically very advanced civilisation that has, for msot of it, regressed to a much more barbaristic state. Although some very advanced technology is still in use on the planet, it cohabits with magical science.
Apart from the dominant humanoid lifeform, the planet features an incredible variety of lifeforms, from monsters to sentient races.