The Alpha Centauri system is a binary star system and the nearest stars to Earth at 4.37 light years.

Alphans (Aquatic)

Earth 616

The aquatic Alpha Centaurians once invaded Earth under the leadership of Dynorr the Stalker. He was repelled by Namor.

Earth 691

Their planet, Arima, was completely submersed in water. When Galactus came to feed upon it, the Keeper (the Silver Surfer) transported them to Centauri IV, home of a blue skinned, primitive culture.

After the Guardians of the Galaxy traveled back in time, they changed the future. The Badoon attacked much earlier than they originally did and made the Alphans extinct.

Centauri IV

The Centaurians of Centauri IV are a blue-skinned, primitive culture that are deeply religious and worship the god Anthos. Their religious text is called the Book of Chants. They are marsupials and carry their young in pouches on their chests. The large red crest on their heads are actually tightly compacted hair follicles. They live in small family groups and are very mystical and warrior-like.

They use weapons similar to American Indians but with the sacred metal Yaka. They use the metal to make knives and arrows, which can be controlled by high pitched whistles to change direction.

Earth 616

Most of what is known of the Alpha Centaurians is from the 691 reality, but several have appeared in the 616 universe. The Alpha Centaurians are also part of the Universal Inhumans, altered much like the Inhumans from Earth.

Earth 691

In this reality, Centauri IV was colonized by Earth. Many of the local tribes avoided the humans. The race was nearly wiped out by the attack of the Badoon in the late 30th century. For some time, Yondu was believed to be the last of his race.

Aside from Photon, a tribe of cave dwellers was discovered to have survived hidden in caves lined with their Yaka metal, which blocks radio waves. Yondu decided to remain with his people and teach them the ways of Anthos.

After the Guardians of the Galaxy went back in time, they changed the course of the future. Having left behind a Centaurian artifact, it's rare Yaka metal attracted a much earlier attack by the Badoon. The Alpha Centaurians were defeated and interbreeding between the species began. More reptilian versions of cross breed appeared and they outlawed the worship of Anthos. Yondu demanded the Guardians repair this 'time jolt.'

Together, Aleta and Starhawk traveled back in time and successfully destroyed the dagger, averting the Badoon invasion and thus repairing the time line.

Language

The tribes of Centauri IV share the same language, of which many words have been revealed.