Life can differ drastically depending on the conditions of the planet in which the alien originated. Throughout human history, many different alien subcultures have been mentioned and described. Life has a tendency to adapt to its environment, as long as the environment provides the necessities for life.
Some of the popular alien life forms are the Zeta Reticuli, the Reptilian Races, The bird like sub culture, The Orion Culture, The Borgs, The Dracos, and the Cat like People.
The Zeta Reticuli come from the Reticulum Solar system that is visible in the southern hemisphere from Earth. The Zeta’s are said to be the common grey alien, referred to as the greys. This race is responsible for most common day abductions and cow mutilations. It was said that the Zeta’s were a destructive race like ourselves. When their environment became unlivable, they migrated underground. Their bodies adapted to their new conditions, and cloning was practiced. During this process, the cranium of the Zeta’s became too big for natural birth. So cloning was used as the primary method of birth. Now these Zeta’s are searching for missing answers, DNA, and valuable experimental materials to once again study and experiment with. This race of aliens is neither friendly or mean. They seem to have no emotion towards humans, and view us as scientific receptacles.
Little is known about other races, but ancient Egyptian hieroglyphics often mention bird and cat like races. The Cat race were looked at as high gods. Many races have visited the Earth, and influenced our evolution.
The Reptilians are a reptile like sub culture. They are believed to be aggressive, and smart. Reptilian Humanoids are mammals, but their blood has a high iron level which gives them a green tone. They are believed to exist on several planets, one being Nibiri.
Throughout the millenniums inter breeding, and merging took place leaving traces of different sub cultures to be carried on. it is a very complicated process narrowing down the exact chain reaction which took place in terms of inter mixing. perhaps someday we will join the Federation Of The Planets and we will have access to such info. But as for now, it’s all speculation.