Biology
The Centauri are humannoid in appearance. While similar in appearace to humans, their are several important differences between the two species.
The sexual organs of the Centauri are quite different than those of humans, and they are in a different location than the human sex organs. Male centauri have six tentacles along the sides of their bodies. The males can strech the tentacles out to several feet. Females have six orifices along the sides of their bodies. The male places the tentacles in the female orifices individually. Each additional tentacle the male places in a female orifice brings an additional level of pleasure for both partners.
The cardio-vascular system of Centauri has two hearts instead of the single heart that humans have. The right heart is a solid mass of muscle which provides most of the force behind the body's blood circulation. The left heart is much more complex - this heart is made up of an intricate system of thousands of veins that help clense the blood in a manner similar to the human kidneys. As a result, a heart attack in the left heart is a very serious matter because the left heart is very difficult to repair. By contrast, a heart attack in the right heart is relatively easy for a competent doctor to repair. Centauri also do not have major blood vessels in their wrists. As a result, a cut in that area would not cause a Centauri to bleed to death.
Centauri males typically wear their hair in Peacock-line fans. The social standing of the male determines the length and style of the hair. Females are usually bald.
The Centauri have extra-sensory perception to varying degrees. Most Centauri have limited ESP, and they often become aware of the time and the circumstances of their deaths. Otherwise, most Centauri only get fleeting glimpses of the future. A few Centauri have very strong ESP, these Centauri are able to see the future much better than the average Centauri. These Centauri are almost always female.
Some Centauri have telepathic ability. Unlike humans, who only had the ability for about a century prior to 2260, the Centauri have had telepaths for a while. Like humans, the degree of telepathic ability varies with the individual.
History
The Centauri were originally one of two intelligent species to occupy their homeworld. The other intelligent species was known as the Xon. The Xon was physically stronger than the Centauri, but the Centauri had the greater intellect. Both sides engaged in a savage war for control of their world, and Centauri intellect won out in the end. By about the human fifth century, the Xon race had died out, which left the Centauri the sole intelligent life form on their world.