Yardrat-jins
The Yardrat-jins are a weak race but they know a lot of important techniques, we only see them once when Goku was telling the story of how he survived the explosion on Namek. They play a brief (but important) role because they teach Goku how to use the Instantaneous Movement technique. They are red with a coned shaped head.
Tsfurujin
The Tsfuru-jins lived on Planet Plant they looked just like the humans and even though they weren`t strong at all their technology was very advanced. They had a rival called the Saiya-jins, the Saiya-jins killed all of the Tsfuru-jins and then the Saiya-jins made it their homeland and they renamed it to Planet Vegeta. When the last Tsfuru-jin died, he said that the Saiya-jins would soon pay for what they have done. Later, in the Dragonball GT, another Tsfuru-jin appears. His name is Bebi and he takes over the entire earth. Then he is destroyed by Super Saiya-jin Goku 4.
Saiya-jins
This is the most fearful race in the whole universe. The Saiya-jins are born with a tails that give them the ability to change into giant monkeys (Oozaru) with ten times their normal power. They were bandits on Planet Plant where the Tsufuru-jin lived, but the Tsufuru-jin managed to keep the saiya-jins out of their city with their technology. One day a whole moon appeard and the Saiya-jins turned into giant mokeys and destroyed the Tsfuru-jins. Later they renamed Planet Plant to Planet Vegeta and they kept the Tsufuru-jins technology. They we also members of the Freeza crew, they had to go to planets and conquer them to destroy them or sell them. Freeza later heard the legend about the legendery Super Saiya-jin which even the strongest man on the universe couldnt defeat him and Freeza decided to destroy the Saiya-jin race because of fear. Only 4 Saiya-jins survived and they are Goku, Vegeta, Nappa, and Raditz.
Androids
Dr. Gero was the creator of all the androids, and they were part of the Red Ribbon Army. The reason for their creations was to take over the world. The andorids look a lot like humans ecxept that they are artificial, and they dont have a "ki". There are three different kinds of androids. One with a human base that rely on an internal power source, the second androids without a human base with an internal power source. The androids with a human base rely on power by absorbing nodes in their hands.
Humans
Humans are the weaker race in the Dragonball/Z/GT saga. The humans on this Earth can have a number of unique characteristics ranging from bald with six dots on their heads (like Krillin) to someone with three eyes. But other than some of these characteristics, most of them look like you and me. The strongest of the humans is Krillin.
Nameks
The Nameks are a peaceful race of uni-sex creatures. There has only been three evil Nameks in the history of the universe (Dr. Slug, Piccolo Daimoah, and Piccolo Jr). The Nameks are all children of Guru, the eldest Namek. The Nameks also do not eat, they only drink water. Nameks are almost exactly like sci-fi aliens in that they are green and have antenae, but are not small. Nameks also have the ability to regenerate appendages, such as arms, when they are cut (or ripped) off.
Majins
Majins are controled by Bebidi and they can be any race (like Saiya-jin, Demon of Hell, or Buu or humans). All Majins are evil, because Bebidi is evil and has majical powers. The Majins look like anyone else but with an evil look. When Bebidi takes over them, they have an "M" (which means Majin) on their forehead.
Change-ling
Change-lings are a very strong race. They have to change forms in order to reach their full power. The number of forms can be from 1-4 forms like 4 for Freeza or 2 for Coola. In Dragonball Z the only Change-lings we hear about is King Kold, Prince Freeza and Coola. They are said to be the strongest family in the whole universe, but all are beaten by the Super Saiya-jins.
Demons
Demons are the people that work behind the scenes at the after-life check-in station. There are also two that run Hell. The demons do weird jobs such as calling forth people to be judged by King Yama and changing out the "Spirit Washing Machine".
Saiba-Men
Saiba-Men are green men from outer space. They start out as little green seeds and are put into the ground. After a few seconds, the Saiba-Men pop out of the ground. The Saiba-Men are rather strong their power level is 1200 each, and they are also used to train to go to fights (such as with the Z Warriors) and to help the Saiya-jins with conquering planents. These were first seen being used by Nappa and Vejeta when they first came to Earth, one Saiba-men killed Yamucha. They are seen once in the Dragonball Z series and once in the Bardock Story.
