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Raargh-Hero, a Kzin Warrior

The Kzinti (singular Kzin) are a species of felinoid aliens known for their bloodthirsty and warlike disposition. From approximately 2360 to 2618 AD humans in the Sol and Alpha Centauri systems fought several protracted interstellar wars with the Kzinti. Kzint tactics are somewhat cat-like in nature, with 'Scream and leap' being the primary mode of attack.

Physical Description & Appearance[]

Kzinti and Humans have a similar biochemistry which hints the existence of a common ancestor in the remote past.[1] This is hinted to have been a result of most species in Known Space evolving from similar forms of yeast that many worlds were seeded with in order to provide food for the now extinct Thrintun. The yeast was one of the only living organisms to survive the Slaver War so it is a safe assumption that most species share this common ancestor.[2]

Kzinti are larger than humans, standing around eight feet (2.4 to 2.8 meters) tall and weighing around 500 lbs (200kg). They have large membrane ears with fur only on the outside of the ear and only about half way up the ear itself, usually appear pink; they can fold back flat against the head for protection during a fight. Their noses are black.[1]

They have a barrel-chested torso with a flexible spine, and large fangs and claws. They stand on two legs like humans (no digitigrade or "backwards-bending" legs), their feet have five toes, their hands end in three fingers and an opposable thumb. Both their hands and feet have retractable claws that are described as "razor-sharp". These claws are nearly as effective as a w'tsai in dispatching prey and are often used in lieu of weapons when hunting non-sentient prey. The tails of Kzinti are naked and are similar in appearance to a rat's, giving rise to the derogatory moniker "rat-cat," used by humans living on occupied Wunderland.

Kzinti are covered with a thick coat of long fur (except the ears, the tail, palms and soles[1]) that comes in various combinations of orange, yellow, and black, with orange being the most common. Though full black coats are rare, and most who have them are taken by the black priests.[3] There are no all-black telepaths for this reason.

The Kzinti adapted to a diet of raw meat. Cooked meat actually makes Kzinti physically ill, although they are able to consume some plant based matter such despite their supposed inhibitions against it. It is uncertain to what extent the Kzin's cardio-vascular and neurological systems differ from humans except for that their blood comes in two colors. Venous blood is orange while arterial blood is purple.[3]

Style of Dress[]

Kzinti rarely wear any clothing except for a vest, which is worn for the pockets it provides rather than for warmth, style or modesty. Apart from this vest, Kzinti tend to prefer the covering of their own fur.

There are exceptions to this norm, however. One example was the nobility of Hssin, who were known to not only wear clothes, but to dress rather foppishly when attending social events.[4] Officers in Chuut-Riit's Fifth Fleet seem to have worn some type of uniform in order to distinguish readily between classes and specializations. For instance, a Captain of the Fleet wore an elaborate satin uniform complete with an eight-pointed rank insignia that incorporated a real diamond.[4] At some point during the occupation of Wunderland, a high quality leather known as kz'eert was produced from the skin of human slaves and used to fashion parts of the Kzinti uniform.[4]


Kzinti evolved from a plains hunting cat on planet Kzin a slightly colder, drier planet than Earth.

Artist's Conception of a Kzin-Hero

The Kzin civilization was in the midst of its medieval feudal period when the Jotok interstellar merchants looking for mercenaries landed and made stealthy First Contact. The Jotok taught the Kzinti how to use high technology weapons and other devices including spacecraft, only to see them rebel and become from employers/masters into slaves (or meal).

They are the first on-going alien contact that humanity has met within the Known Space universe. The first contact with humanity ends the human golden era of peace.[5]

The Man-Kzin Wars[]

The Kzinti were the first alien species encountered by Humans, apart from a single Thrint and the Pak Protector Phssthpok, at the same time when they attacked the Earth colony of Wunderland, beginning a series of bloody wars that lasted for two centuries.[1]

A total of five additional Man-Kzin wars take place by the time Beowulf Schaeffer commented "The Kzinti aren't really a threat. They'll always attack before they're ready".[6] With decreasingly impressive logistical and technological advantages, each war results in the confiscation or liberation of one or more colony planets by the humans. In this way humanity contacts the Pierin and Kdatlyno, former slave species, and takes over worlds such as Canyon (formerly Warhead) and Fafnir (formerly Shasht). Several of the stories of the Man-Kzin Wars depict the nearest Human colony at Alpha Centauri, called Wunderland.

During wartime, and at other times, Kzinti interrogate humans using a device called the hot needle of inquiry, which is also used to punish Kzinti who violate their code of honor. The ship piloted by Speaker-to-Animals is called the Hot Needle of Inquiry in honor of this torture device.[7]

The Kzin reverses were deliberately engineered by the Pierson's Puppeteers, who lured the Outsiders to We Made It in the first place. The Puppeteers had hoped that the culling of a quarter to a third of the more aggressive members of the Kzinti with every war would result in a more peaceful race, or at least one that was capable of coexisting with other species without trying to kill and eat them at every turn.[8] This shift in Kzin attitudes succeeded spectacularly, although the Kzinti themselves do not think very highly of the changes, nor of the price they paid to achieve them. In fact, a fringe faction of the Kzinti known as the Kdaptists, frustrated with the reversals their race had suffered against humanity, went so far as to adopt the human concept that God had created humanity (not Kzinti) in His image, and that He favors and protects humans over other races.

As the Puppeteers expected, a form of "natural" selection occurred, with the more mindlessly aggressive Kzinti dying in ill-advised wars and the more moderate, intelligent, and cautious Kzinti surviving, presumably to think long and hard about the consequences of starting yet another war. By the time the Kzinti attained the level of sophistication and foresight needed to win against humans, they no longer had the numbers or the drive to do so.

At one point, Louis Wu, while visiting the Kzin homeworld and given access to the Kzinti Patriarch's game preserve, was confronted by a young Kzintosh and his father. When the youngster asked "Are they good to eat?", Louis Wu responded with a grin (baring of the teeth being a Kzin challenge to battle) and the older Kzin responded "NO". Wu muses that it would be safer for the young Kzin to eat arsenic than a human being.

Part of the reason humanity is such a dangerous enemy is the psychological blind spot the Kzinti have toward human females. Since the Kzinti have bred intelligence out of their own females, an inexperienced Kzin is sometimes careless enough to leave human females to their own devices, usually with fatal results to that particular Kzin. A combat-trained human female is a Hero's worst nightmare. The Kzinti term for any particularly competent human female soldier is "Manrret" (singular) or "Manrretti" (plural), so named out of a sense of gallows humor regarding lethal encounters with same. From the Kzinti point of view a Manrret's stamina, speed, reflexes, pain tolerance, and reasoning capability (enhanced intuition by virtue of increased interconnectedness between the left and right halves of the human female brain) are far superior to a Man's. This gives some Kzin reason for considering each of the genders of humanity to be a separate alien species.

At the end of the last Man-Kzin War, around 2618, Kzin was occupied and disarmed by human armies.


Kzinti society is extremely male-dominated and aggressive.[1] Their empire is called the Patriarchy and is ruled by a single Kzintosh who is referred to only as the Patriarch, a hereditary title. The Patriarch is of the Riit line meaning Chuut-Riit and Vaemar-Riit are his descendants. All conquests by the Kzin are made in the name of the Patriarch although the religious institution of the Patriarchy also exerts a strong influence.


The Kzin call themselves "Heroes" or the "Heroic Race" and because they believe themselves to be "heroes", their society places a very high value on "acting Heroic" and behaving in a heroic fashion. The word Kzinti actually means Hero in the Kzin tongue. To Kzin society, "heroic" means being honorable and having integrity. Honor being more important than profit, Kzin don't typically lie or bluff, promises are binding, and personal danger is never taken in consideration. This lack of subterfuge is evidenced in the favorite strategy of the Kzin Patriarch, commonly referred to as "Scream and Leap."[1] The Kzin culture is so focused on the concept of retaining and gaining honor that it has been speculated that at some point in their history their genes were actually adapted to develop a greater tendency towards traits that were considered to be "heroic."

Strakh is a sort of currency or favor system since. For example if the patriarch gets meat from a sellers market stand the seller gains considerable strakh which will bring honor to the seller allowing him to get better customers which leads to more strakh, which gives the seller a higher status within the community.


Intelligent Kzinrett

Once Kzin gained access to Jotoki genetic manipulation technology, they started manipulating themselves in order to bring out the most "heroic" qualities and recede undesired ones. To this end, because females are not valued except as bearers of children, the male-dominated Kzin society bred (most of) their own females into sub-sapience. In the novel Treasure Planet it is hypothesized that Kzin scientists genetically modified the females of the species as the differences between the brain chemistry and metabolism between the two genders were too radical to be explained by evolutionary means. Kzinti females (s. Kzinrett, pl. Kzinretti) have a vocabulary of fewer than a hundred word/sounds and primarily instinct-driven behavior, and are treated as chattel by males (s. Kzintosh, pl. Kzintoshi). Kzinti society explains this by stating the Fanged God removed Kzinrrets' souls as punishment for an attempted rebellion against him shortly after he created Kzin. In reality it was a result of the Kzintosh's desire to maintain patriarchal dominance over Kzin society.[3]However some tribes, long isolated from the Patriarchy, were spared the genetic modifications and still produce sentient females, as well as certain bloodline, Occasionally a Kzinrett will be born that has intelligence equal to or even superior to their male counterparts. Although such occurrences are rare, there seems to be a secret society of intelligent Kzinretti who play dumb while biding their time for a future when all Kzinretti can be restored to their normal state. Karan, the wife of Vaemar-Riit, as well as some of her descendants were intelligent Kzinretti.[9][3]


Kzintoshi are born without names which they must earn through valorous deeds. They are originally known by their relation to their father when they are kittens, although some kittens, especially those born into aristocratic families, were called by nicknames during adolescence.[3] After maturity, they are known by their rank or occupation. A Kzin who has performed a great deed will be granted a partial name by a superior; a further, greater deed earns a full name, the second of which is the family name. Only Heroes who have earned a partial name are allowed to breed. The number and quality of the kzinretti in a particular Hero's harem are based on the name that that Hero has attained, which is itself a representation of the Hero's honor. In fact, a Kzin's proper name, while hard to translate into a human language, contained tightly coded signals that would relay information about the Hero and his deeds to other Kzin.[3]

In rare instances, a sufficiently illustrious accomplishment will earn a nameless one a full name in one fell swoop. An example of the latter is the granting of a full name to Trainer-of-Slaves, who singlehandedly delivered a fully-working hyperdrive to the Patriarchy thus earning the full name Graaf-Nig.[10]

An example of a Kzin's naming transition would be:

  • Birth description: Third-Son of Khral-Hrag
  • Occupation description: Weapons-Technician
  • Partial name: Frep-Technician
  • Full name: Frep-Hrag

There were several notable exceptions to Kzin naming conventions, especially after the human liberation of Wunderland around 2420 C.E. For instance, some members of the -Riit family, who have held the office of Kzinti Patriarch for uncounted generations, retained names that they were given as mere kittens. Vaemar, Orlando, Orion, and Marthar all appear to have kept their childhood monikers.[11][3] However, the heir-apparent to the Riit throne, "Pouncer", does not receive a name until it is earned by deed.[12] Other Heroes who were known to have committed great acts of valor or achieved promotions that would otherwise grant them full names, are inexplicably still called by partial names, although this may simply be a shortening of the entire name on the speakers part. Examples include Raargh-Hero as well as Traat-Admiral.[11] In addition, after the liberation of Wunderland, many of the Wunderkzin began to develop a culture that was in many ways distinct from the Patriarch. Part of this distinction was for Kzin on the outskirts of the Patriarchy to give themselves nicknames based on their own perceived attributes, or in some cases, even claim titles under dubious circumstances. Such behavior was more prevalent among the criminal element of the Kzin, especially pirates, and to break such social mores would have been unheard of on the Kzin home world.[3]


The Kzin Patriarchy follows a unified religion, worshiping a deity known as The Fanged God. Their priesthood is comprised of all black members of the race, selected at birth.[12] How seriously the individual Kzinti take their religion is uncertain, but it is evident that the priesthood and the belief in The Fanged God do have a large influence on Kzin society as a whole. In fact, according the the priesthood, it is The Fanged God who has promised that all other species will be subjugated by the Kzin. This doctrine is sited by the Kzin to justify their conquering and destruction of other cultures, although many began to question the idea after the Patriarchy suffered its first real defeat at the hands of mankind.

During the Man-Kzin Wars, a cult formed on and around Wunderland based on the teachings of Kdapt-Pilot, later Kdapt-prophet. Kdaptism taught that the Fanged God was false, and that the true God was Bearded and resembled humans instead of Kzin. Though this religion was most often the venue of low-born families, there were a few Kzinti in the greater nobility who also subscribed to Kdaptism. In 2445 CE a member of the Kdaptist cult on Tiamet was implicated in the murder and mutilation of a human woman, although the allegations later proved to be false.[13]

When Kdaptist disciples prayed, they wore masks of human skin in the hopes of confusing the Creator long enough for the Kzinti to win the war. Human psychologists suggest that hundreds of years of steady losses of their greatest warriors tore at the social and psychological infrastructure of the Kzinti race, who believed their destiny to be no less than domination of the universe. The disbelief created by the losses in turn created Kdaptism.


A small percentage of Kzinti are stunted, and forced into addiction of a drug derived from the lymph of a sthondat which is designed to bring out and amplify the telepathic abilities that lie dormant in every Kzinti. "Only one out of every thousand Kzinti telepaths retain their sanity, but become shivering neurotics."[12] The few who survive are left with telepathic ability but addiction to the sthondat drug is a steep price to pay as it takes a huge physical toll on the user. Even the strongest telepaths avoid the drugs unless they are required to use them as the effects are so potent. One dose can last up to eight hours and requires an extensive period of recuperation if the telepath wishes to avoid serious irreversible damage to their system. Using the power of telepathy is itself very painful for both the telepath and the target. The target will often experience seizure like systems and intense rolling pain in the head and neck, sometimes even leading to loss of consciousness. The painful and health damaging effects of both telepathy and the drug used to amplify the ability both contribute to the hagard appearance of Kzin telepaths.

The drug enables a trained telepath to reach out and touch minds as far away as 2500 kilometers. No known sentient is immune to the effects of the Kzin telepaths with the exception of the Bandersnatchi and possibly the Thrint (due to their own telepathic abilities).

Telepaths are tolerated by the warrior class due to the specialized use of their skill, otherwise they endure a low-caste position in society, just above the status of slaves, with the occasional slave being considered of a higher social status. Telepaths rarely, if ever, earn a name, and they aren't legally allowed to breed.

Kzinti telepaths are easily identified by their unkempt appearance, matted fur, and bouts of shivering. They sleep for most of their leisure hours. Their bedraggled, distraught appearance is shameful for a Kzinti.

Since the end of the last Man-Kzin war, Kzin telepaths are only encountered in espionage operations, piracy, and other illegal operations. Although new generations of Kzin born on Wunderland have set up their own Telepathic Investigation businesses.


They speak in a hissing language called the Hero's Tongue, which in its written form resembles commas and periods. It is extremely difficult for Humans to learn, however the Kzinti show an affinity to learn alien languages.[1] On occupied Wunderland, a shared language developed over time between the surviving human population and their Kzin overlords. This language, really a patois, was referred to derogatorily as the Slave's Tongue. While some humans were able to master the Hero's Tongue, the Kzin generally did try to speak human languages, even if they understood them, although there were notable exceptions. The differing physiologies of the two species also presented challenges when attempting to pronounce the others language so the Slaves Patois provided a more accessible means of communication between the two species, if an unequal one.[11][4]


Kzinti control and utilize a wide array of technologies, most of which have been captured from conquered species, notably the Jotoki.[4] Within Kzin society, those who make a living by pursuing scientific interests are looked down on and treated with suspicion. As being a warrior is considered the highest value, there is a dearth of capable Kzin scientists available in the Patriarchy. Because of this, the Kzinti rely heavily on their Jotoki slaves to maintain the technology that helps them keep order across the Patriarchy. With a few exceptions, there are not many Kzin who understand how the technologies they utilize actually work. One notable exception was the Kzin called Mellow-Yellow also known as Trainer-Of-Slaves.

Human Influence[]

During and after the Kzinti occupation of Wunderland, their close proximity to humans resulted in several profound changes to both cultures. Although they would not admit it, the Kzinti of Wunderland picked up many quirks and ideas from their enemies. A few of the things that became commonplace in the Patriarchy as a direct result of man's influence were toilet paper, ice-cream, whiskey and a great liking for the game of chess.[9][3]

Conquered Races[]


The Kzin were initially introduced in Niven's story "The Warriors" (originally in Worlds of If, 1966) and "The Soft Weapon," (1967), both collected in Neutron Star (1968). A Kzin character, Speaker-to-Animals, subsequently played a major role in Niven's award-winning Ringworld (1970), giving considerably more background of the Kzin and their interactions with human civilizations. Following this, Niven gave permission to several friends to write stories taking place in the time following "The Warriors" but before "The Soft Weapon;" these stories (including a handful by Niven) were collected in a number of volumes of The Man-Kzin Wars, which eventually reached eleven volumes, the first published June 1988.

Other Appearances[]

Star Trek[]

The Kzinti also appeared, along with allusions to slavers and stasis boxes, in The Slaver Weapon, an episode of Star Trek: The Animated Series written by Niven, as a proud and carnivorous species. The Slaver Weapon was an adaptation of Niven's story The Soft Weapon. They were incorporated into the Star Fleet Universe where theyMobile became a powerful empire known as the Kzinti Hegemony, mortal enemies of that universe's Lyran Star Empire - although it is alluded that the Kzinti and Lyrans share common ancestry, a claim both sides violently reject.

In the Star Trek Logs written by Alan Dean Foster, it has been hinted that the Caitians are an offshoot race of archaic Kzinti (where both genders are intelligent) who have renounced conquest. According to a memory of Lieutenant M'Ress, secondary communications officer in the Star Trek Logs, the Catian and Kzinti languages are similar enough that M'Ress can pass as a Kzin just long enough for her to send off a distress call from a Kzin raiding ship.

The Kzinti reappear in the comic The Wristwatch Plantation, also by Niven (and which included the Bebebebeque from his Draco Tavern stories). Kzin appeared on a star map seen in several episodes of Star Trek: The Next Generation, and a feline stripper from Star Trek V: The Final Frontier was referred to backstage as a kzinrret. The name of the Tzenkethi mentioned in Star Trek: Deep Space Nine was partially based on the Kzin, and had Star Trek: Enterprise not been cancelled, the Kzinti would have appeared in the fifth season. An unnammed Kzinti also serves on the U.S.S. Cerritos, in Star Trek: Lower Decks.

The instruction manual for the PC game Star Fleet Command clearly refers to the Kzinti by name in the background story for the rival race, the Lyrans. This race is introduced in Star Fleet Command II: Empires at War by simply changing the Kzinti Hegemony to the Mirak Star League.

In the Star Trek: Picard episode "Nepenthe," Riker mentions that he has been having trouble with the Kzinti on the planet Nepenthe.

Star Fleet Universe (SFU)[]

Please note that in the Star Fleet Universe, the Kzin/Kzinti distinction between singular and plural is replaced with Kzinti/Kzintis.

The Kzintis in the SFU - who have traits setting them apart (no bat ears, sentient females, Kzinti/Kzintis as singular/plural etc) from the Kzinti of Niven's works - have fought wars with all of their neighbours, the Federation, the Klingon Empire and their perennial nemesis, the Lyran Star Empire, and are long-standing allies - or more accurately, co-belligerents - of the Hydran Kingdom. The Hegemony eventually formed a tentative accord with the Federation and allied with them in the General War, but they have been involved in major wars with the Klingons and Lyrans, such as the Four Powers War and the General War itself, in which a substantial region of their territory was occupied by their Coalition enemies and two full-scale assaults were made on the Kzinti homeworld of Kzintai. Eventually with Federation assistance they forced the Coalition forces from their territory, but after the War ended they were involved in a Civil War as a disgruntled faction - which had been opposed to the Hegemony's ruling Patriarch and sought refuge and developed a power base in the WYN Cluster - launched an attempted coup of the Hegemony itself in the WYN War of Return.

In the fictional variant of the Star Fleet Universe as represented in the games Star Fleet Command II: Empires at War and Star Fleet Command: Orion Pirates from Taldren, the Kzintis were renamed as the Mirak.

Dungeons & Dragons[]

The fifth anniversary issue of Dragon magazine (#50, June 1981), included an article detailing the Kzinti as a race for the Advanced Dungeons & Dragons game.[14]

Wing Commander[]

The PC game series Wing Commander features a race of anthropomorphic cats very similar to the Kzin called the Kilrathi. In tribute, a scenario in Wing Commander II takes place in the "Niven System".

Kzinti Characters[]

An incomplete list of known Kzin


  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 Concise Encyclopedia
  3. 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 Hal Colebatch & Jessica Q Fox - Treasure Planet (novel)
  4. 4.0 4.1 4.2 4.3 4.4 4.5 4.6 The Survivor - Donald Kingsbury (Man-Kzin Wars IV)
  5. The Warriors - Larry Niven (Man-Kzin Wars)
  6. Grendel
  7. The Ringworld Engineers
  8. Ringworld (novel)
  9. 9.0 9.1 9.2 9.3 9.4 Grossgeister Swamp - Hal Colebatch (Man-Kzin Wars XI)
  10. The Heroic Myth of Lieutenant Nora Argamentine - Donald Kingsbury (Man-Kzin Wars VI)
  11. 11.0 11.1 11.2 11.3 11.4 His Sergeant's Honor; Man-Kzin Wars IX
  12. 12.0 12.1 12.2 Destiny's Forge - Paul Chafe (2006)
  13. Windows of the Soul; Man-Kzin Wars IX
  14. Dragon #50, June 1981 (
  15. The Children's Hour; Man-Kzin Wars II
  16. Music Box; Man-Kzin Wars X The Wunder War
  17. 17.0 17.1 The Corporal In The Caves; Man-Kzin Wars X
  18. Three At Table; Man-Kzin Warz XI
  19. Catspaws - Hal Colebatch (Man-Kzin Wars XI)

External links[]