Narn

The Narn are a humanoid species that have on two occasions been conquered by the Centauri.

Biology
Though somewhat reptilian in appearance, the Narn actually have more in common with Earth marsupials and felines than reptiles. As with many species, Narn sexual reproduction is heterosexual and viviparous, beginning with a direct male-to-female mating in which the female carries the young until birth. After which they are transferred to the male's abdominal pouch where they are nurtured for the next three months, until they are strong enough to survive outside of their father's body. From this process comes the terms "pouchling" and "pouchbrother/sister" which can culturally be used as an insult when directed at an adult, insinuating that they are too weak and helpless to survive by themselves. Typically Narn may conceive two or three children in a single brood and have a relatively low infant mortality rate. Narns usually only take single partners with whom they mate for life, though this is purely cultural and not a biological necessity.

The Narn DNA structure is open to genetic manipulation and as such Narns have become adept at gene-engineering, both of their own genome and that of other humanoid races. One common modification comes in the form of gill implants, a painful but efficient way to process non-standard foreign atmospheres. Narns have also researched into the possibility of inter-species breeding with Humans, though with the aid of extensive genetic adjustment.(Geth)

Mindwalkers
Though the Narn were among the hundred or so races genetically altered by the Vorlons to breed telepaths (refereed to as "Na'fariki", or "Mindwalkers" in the Book of G'Quan), they were all wiped out by the Shadows during the First Shadow Ship of Tear Since the end of the First Centauri Occupation of Narn, the Narn Regime became obsessed with gaining whatever advantages they could and openly attempted to require the telepath gene. Biologically, the telepathic gene is present, but since the pogrom that wiped out the ancient telepaths the gene was too weak to naturally breed a viable teep with their own eugenics program. This led to several attempts by the Narn to buy the DNA of telepaths from other races in the hope that it could be combined with their own and begin breeding new Narn telepaths.

In terms of appearance the Narn are humanoid, hairless, generally taller than most humans and of a stocky build and have a yellow-orange complexion, distinctly mottled with patters of brown and/or green spots. Narn eyes are, for the most part, tinted red and gift them with very acute vision encompassing the infra-red spectrum.The Official Babylon 5 Magazine: Volume 1, Issue #3 (Nov 1997) - Page 26 (A Brief History of Narn)

A supple yet tough bone structure and thick skin endows them with a higher degree of resilience to physical harm than most other humanoids; a trait the Centauri "pain technicians" have tested to its limit. Aside from mere protection, their tough, leathery epidermis not only manages both the internal and external body temperature but also stores quantities of fluids and energy that allow Narn to hibernate for several days at a time. This ability to regulate their bodies' water also means that common alcoholic intoxicants have little or no effect, except in considerable quantities.

In 2257 Ambassador G'Kar proposed just such a deal to Babylon 5's Human Commercial telepath Lyta Alexander and in 2258 his aide Na'Toth made a similar proposal to Alisa Beldon, a newly manifested P10 Human.Gath The Gathering Legacies In 2260 then Citizen G'Kar purchased a small quantity of Dust in hopes of using it as a weapon against the Centauri occupation, though a small sample was able the activate the dormant telepath gene, the result was unstable and with the intervention of the Psi Corps, the drugs were seized before the purchase could take place.Dust to Dust The Narns' perseverance finally paid off in 2262 when Lyta Alexander, now a leader of a group of Rogue Telepaths agreed to supply the Narn Regime with DNA from as many Human telepaths as they wanted in exchange for an undisclosed, but extremely large sum of money, at least five deep-range starships and an agreement that the transaction be made in absolute secrecy. Darkness Ascending