A science fiction species co-authored by Creator/AnneMcCaffrey, Margaret Ball and Elizabeth Ann Scarborough. The first series follows the life of the eponymous unicorn girl Acorna from the discovery of her escape pod by three miners to her rediscovering her heritage and her place in the universe. The sequel, ''Acorna's Children'' is currently a trilogy.

!! This series provides examples of:
* AsteroidMiner: Calum, Rafik and Gill are this when they come across Acorna's escape pod.
* ALoadOfBull: The Nirii are a [[TheStoic stoic]] telepathic bovine-like alien species.
%%* CatsAreMean: Roadkill (aka RK).
* CatsAreSuperior: Roadkill again and the entire Makahomian Temple Cat species in general.
* [[CatBoy Cat Guy]]: Grimalkin's preferred humanoid form is described as this.
* CoitusInterruptus : When Acorna and Aari ''finally'' get together, TheirFirstTime is interrupted by Nadhari, who is both mortified that she interrupted them and upset that no one gave her a heads up that Acorna (whom she was looking for) was "busy."
* ConstructedLanguage: The authors over the books have put together quite a few grammar and pronunciation rules for the Linyaari language as well as a small word corpus.
%%* CoolOldLady: Grandam Naadiina
* CrapsackWorld: Kezdet. Rife with corruption, child slavery and exploitation.
* EasilyThwartedAlienInvasion: The Khleevi fleet heading for Kezdet were easily chased off by the simple fact that they were capable of fighting back. Once they find a certain plant, destroying Khleevi infestations became as easy as spraying for weeds.
* EmotionEater: The Khleevi (especially their offspring.) feed on the pain and fear they cause their victims. The Linyaari due to their pacifist nature, empathic ability and rapid healing are considered a delicacy.
* EveryoneCanSeeIt: Everyone knew Acorna and Aari were meant for each other, except Acorna and Aari.
* FumblingTheGauntlet: In Linyaari culture, Acorna's human-style smiling (with teeth showing) basically means "I'm about to attack you."
%%* HappilyMarried: Hafiz and Karina
* HealingHands: Or Healing Horns in the case of the Linyaari. In addition to healing wounds, the horns also allow them to purify substances (including neutralising poisons) and communicate telepathically .
* HordeOfAlienLocusts: The Khleevi can be considered this. It is implied in ''Acorna's Triumph'' that they have a scoured a galaxy or two of organic life.
* HumansAreWarriors: The Khleevi learnt the hard way at the end of ''Acorna's Quest''. They were shocked to find a species which actually fought back when attacked, and resolved to stay away from humanity.
* IThoughtEveryoneCouldDoThat: The Linyaari didn't realize that not everyone knew how to make paint that could withstand interstellar travel.
* ISOStandardHumanSpaceship: The Linyaari are baffled by the uniform, uncolored nature of human starships. On the flip side, humans find the colors on Linyaari craft loud and garish.
%%* JerkWithAHeartOfGold: Tharrinye
* NiceHat: The Linyaari often wear special horn hats which double as PsychicBlockDefense.
%%* ObstructiveBureaucrat: Liriili
* PerfectPacifistPeople: The Linyaari, who preferred to run and abandon their world rather than fight the Khleevi once they saw they couldn't be reasoned with. This is partly due to the nature of their abilities and partly due to their society.
** Acorna and Aari, due to their past experiences, lack the Linyaari's cultural and psychological aversions and are much more pragmatic about the use of violence.
*** The Nirii take this UpToEleven: They consider the Linyaari HotBlooded.
* {{Precursors}}: The Ancestral Friends, who called themselves the Hosts, are the precursors of the Linyaari, Makahomian Temple Cats and probably many other races through a combination of [[{{ShapeShifting}} Shapeshifting]], genetic engineering and BoldlyComing.
* PhonyPsychic: Karina is initially depicted as this in ''Acorna's Quest''. Subverted throughout the series where it is shown that she actually has the gift but just not as much she believes.
** Played hilariously with her first interactions with actual psychics, the Linyaari, when her standard-phony-psychic visualization exercises actually shut down the rudimentary communication that they've established.
-->"No luck, all I'm getting now is blue."
* QuestForTheRest: Inverted - Acorna's family was looking for ''her.''
* ShapeshifterModeLock: [[spoiler: Grimalkin's]] ultimate fate at the end of ''Acorna's Triumph'', trapped in the form of [[spoiler:a kitten]] by his superiors.
* [[ShellShockedVeteran Shell Shocked Survivor]]: Aari, horrifically tortured by the Khleevi then abandoned on his dying homeworld as the sole survivor. He has issues.
* TheSwearJar: After the miners take in a little alien girl they institute this, just because they don't want her learning those particular words.
* {{Telepathy}}: Quite a few species in the series are telepathic.
* TimeTravel: [[spoiler: The Hosts had this down to an art form. Becomes a centre plot point in ''Acorna's Search'' and ''Acorna's Triumph'']]
%%* TheTrickster: Grimalkin fits the archtype.
* {{Unicorn}}: Acorna and her species the Linyaari are [[InnocentAliens Alien]] PettingZooPeople version and share many of the qualities that unicorns are said to have.
** Also the Ancestors, who are the descendents of the unicorns who were rescued from Earth by the Ancestral Friends.
* WeatherControlMachine: Central to one of the major plots in ''Acorna's Quest''.
* WhoNamesTheirKidDude: Acorna's name is unpronounceable in Linyaari, the nearest equivalent is Khornya which incidentally means "One Horn" in Linyaari. Needless to say, many are amused and bemused by her name.