Bio on Ra'zac

When a Ra'zac is hatched, it is referred to as a pupa. It develops a roughly human exoskeleton, allowing it to remain somewhat inconspicuous in the company of its favorite prey, humans. During the pupae stage, they wear black cloaks to help hide their true form. In this stage, Ra'zac feed exclusively on human beings, but upon maturing will kill and eat anything that moves.

When the pupae reaches the first full moon of its twentieth year, it sheds its exoskeleton,spread its wings that have developed from a bulge on its back, emerging as a fully grown Lethrblaka, said to resemble a type of "monstrous dark dragon". The flying mounts used by the Ra'zac were actually their parents, the Lethrblaka. Lethrblaka had the intelligence of a dragon, albeit a cruel and twisted one, but they are much more intelligent than the younger Ra'zac and could give out ear-splitting shrieks that most are not able to stand. Magic users, however, could counter it by casting a spell to "empty their ears". The Lethrblaka then reproduce oviparously, renewing their cycle of life.

It is unknown where the Ra'zac originated, but they are not native to Alagaësia. It is most likely they came from whatever place humans abandoned, and they may be the reason that the humans abandoned this place.

For many years the creatures roamed wild, killing and devouring humans before the Dragon Riders agreed to put an end to it. During the bloody Ra'zac War, nearly the entire Ra'zac race was exterminated, except for two Lethrblaka who survived.

Ra'zac had no access to magic, but they were very effective against mages because their minds cannot be observed or possibly their minds are so alien to mages that they can't sense them at all.The Ra'zac had a human ally in Galbatorix, who would cast protective wards over them.

The Ra'zac possessed superhuman strength, speed, agility, and stamina, equal to an elf. However, they also possessed an ability no elf, shade, or even dragon rider had; an evil breath that fogs the minds of humans(most likely a poisonous gas that helps them hunt humans) and make most people incapable of doing anything. A dragon Rider is almost completely immune due to their bond with their dragons, who are not affected at all. The Ra'zac also had strong exoskeletons which was as hard and strong as armor, and protected the Ra'zac from weak blows without slowing them down with bulky excess weight.

In addition to these abilities, their senses were very strong; they could track scents like hounds, see on a cloudy night or even in complete darkness. But perhaps the Ra'zac's greatest power was the special shields that protected their minds. Even the best human mindbreakers could not detect a Ra'zac's mind. This made it impossible to breach or control them with mental powers, unless the Ra'zac consented to it. It also made the Ra'zac excellent assassins, for not even mages would be able to detect them until it was too late.

The Ra'zac spoke in their own language of sharp clicks, clacks, clucks, shrieks, chirps and other bird-like sounds. None of this language was translated and the calls may have been unintelligible and even unpronounceable to all but the Ra'zac.

However, the Ra'zac had weaknesses as well. Because their eyes were so sensitive to brightness, strong light pained them, though it was not fatal and wouldn't stop a Ra'zac if they were determined. Powerful light, such as that conjured by the "kveykva" spell would momentarily stun a Ra'zac. Ra'zac also were unable to swim, possibly because of their exoskeleton, as a result, they had a morbid fear of (deep) water and thus kept away from it.

Both Ra'zac were cunning and cruel, but rather narrow-minded. They were capable of conscious thought and consideration, but were not as intelligent as humans, dwarves, elves, or dragons.

The shorter Ra'zac has been consistently portrayed as more blunt, cruel, and impulsive than the taller one; both traits could correspond to age. When talking with Sloan, the shorter one was significantly more threatening than their taller counterpart. When they captured Eragon and Brom, the shorter one suggested just killing Brom, rather than drugging him and putting up with the trouble he caused.