She appears to have a rather fluctuating personality depending on the situation she is in. When Ryn tells her about her colony's sufferings ranging from lack of food to low birth rate, Tia promises her that she will help her. Tia also appears to be philosophical thanks to the time spent in captivity. In her view, she believes that merfolk are the most evolved species on the planet and their job is to restore the balance of nature, something she believes humans are incapable of doing. Whenever her plans get foiled or if anyone tried to intervene, she would not hesitate to injure or even kill them. However, she is not without mercy, as she warns Ryn about the consequences of intervening.
In her human form, Tia appears as a tall, young woman with black, wavy hair flowing down past her shoulders. She has slightly tanned skin and purple eyes. So far she has been seen wearing a black jacket with a white shirt and black pants.
In her mermaid form, Tia appears to be very similar to the other mermaids except for some differences. She has the same gray scales as the other mermaids but also has reddish-orange scales that glow underwater and her pelvic fins are much wider and more flexible than those of Ryn and her colony.
Tia was banished from her tribe after trying to fight off a tentacled, serpent-like predator called The Ga'anda, and getting injured in the process. She was the one who killed Charles Pownall after he massacred her people. Later on she became pregnant with a child and she was subsequently captured by Russian scientists 10 years before the events of the series. During that time, she had lost her child to the Russian government who found out about her Siren song and lobotomized her, leaving her unable to sing. In captivity, she learned many things from humans: sciences, engineering, technology, history, and even fighting. She had a caretaker whom she fell in love with. After some time, she heard intelligence reports about another one of her kind being held captive by the U.S Military, with Boris' help she managed to escape in order to find it.
Throughout the Series
Tia is disguised as a flight attendant who boards a private jet that departs from Vladivostok, Russia to Washington state. While in the air, she kills the crew with an ice pick and sets the autopilot to have the plane plummet into the Pacific Ocean with the passengers still inside. She jumps out into the air deploying her parachute and landing in the water where she transitions into her mermaid form, she swims her way to Bristol Cove. Tia arrives at Helen's shop and meets Ryn, where she introduces herself to Ben and Maddie. After learning her sister Donna's corpse was stolen from its grave she suggests to Ryn that the humans responsible should be killed as a consequences, Ben dismisses it. Tia uses Ben's phone to text Commander David Kyle to lure him out onto the docks, when he arrives she ambushes him, stabs him with her barbed stinger and drags him into the water killing him.
"Revelations" is when Katrina meets Tia, learning that they both are from the same tribe. After a brief fight, Tia decides to leave to unite the Merfolk tribes against the humans ignoring Ryn's point of view. Despite her clear warning Ryn goes after Tia, following her out to Carson Sound her intervention prevents Tia from harming Ben's father. After Tia injures Ryn during their fight, she is forced to retreat after she is outnumbered Ryn's colony.
The episode "Survivor" is when she finds her former mermaid tribe and kills the current Alpha to take her place. After a couple of days of roaming the seas, she manages to successfully unite other tribe leaders to form an army of her own.
In "Mommy and Me" Tia's tribe follows Hunter and finds Ryn's colony hiding in an underwater plane wreckage. Surrounded, Tia gives them a choice: either join her tribe, or die. Katrina chooses to join Tia as her tribe is the one she was born in, later it is mentioned by Cami that Tia let her go but has killed the other merfolk who tried to fight back.
"The Island" is when she fights with Ryn's tribe. She gathers all the Merfolk who were killed in the battle, she learns that Hunter is alive and says she will be loyal, but Tia does not believe that to be true. She demands answers and Hunter tells her about Ryn's baby.
In "Northern Exposure", she shows Hunter newly-acquired weapons: explosives that can be used underwater. She uses them to sink three fishing ships located in various bodies of water off the coasts of Canada and Alaska, with her path ending near Nome, Alaska. She also uses them destroy the underwater echo chamber that Ben, Ryn and Maddie visited in "Serenity"
In "Til Death Do Us Part", she was repelled by Yura's tribe. She and Hunter are drinking at a bar in Dunay, Russia where she sees a news report of a "sonic attack" on a municipal office in Ternipol, Ukraine, Tia learns that her Russian captors have weaponized her song. She returns to Vladivostok and reunites with a man named Boris. She accesses the contents of his laptop and obtains the audio file of her Siren Song, which she uses on a larger scale in "A Voice in the Dark" by transmitting it through everyone's cellphones.
"The Toll of the Sea" is the climax. Tia transmits a live broadcast to all the countries in the world delivering her message to the humans. In the ocean, she holds Hope captive in the plane wreckage. Tia and her warriors are led away by Ryn where she is ambushed by her tribe. Just as she summons her army, Yura's tribe joins the fight alongside Ryn in the Siren War. She is slain by Ryn with two spears to the chest, her body sinks down to the bottom of a chasm bleeding.
She and Tia were both born in the same tribe as each other, she did not hesitate to rejoin. She was more loyal to Tia than she ever has been to Ryn, despite being raised by her colony. After she slit her own throat in "The Island" Tia's Merfolk lay her corpse next to the other slain warriors.
Tia meets Ryn in "Borders" when she finds her at Helen's shop, she shares her story and her point of view on humankind. She agrees to follow until she learns about Tia's true intentions, their first fight takes place out at Carson Sound where her colony outnumbers Tia forcing her to retreat. In the climax of "The Toll of the Sea", her colony fights Ryn and Yura's tribes. During the battle, Ryn takes her spear and Tia's and stabs her through the chest.
Tia first crosses paths with Hunter after her and Ryn's tribe fight on an island off the coast of Bristol Cove. She discovers that she survived from her injuries, she reluctantly decides that she will be loyal to Tia. Tia sees through her lies and demands answers, Hunter divulges the existence of Ryn's daughter Hope sparing herself from death, from the on she goes with Tia wherever she goes. At a bar in Dunay, Russia Tia has Hunter drink shots of alcohol, her inability to do so is what proves her vulnerability. In "The Toll of the Sea" she beings Hope to Tia after kidnapping her from Caspian Ranch in an attempt to prove her loyalty but she chains her to the floor abandoning her.
The Russian Government proved to be oppressive to Tia. While Tia was pregnant with her child, a research vessel discovered her and was captured. She was then transported to a government facility, the personnel there would then address her as "Vodnyy Zver" and keep her imprisoned for the next 10 years. They tortured Tia, trained her to be an expert tactician, and above all made her into a weapon.
Boris was a scientist affiliated with the Russian government, he was assigned to be Tia's caretaker while the rest of the science staff conducted their agonizing experiments on her. Throughout the span of 10 years, Tia built trust with Boris and also developed feelings for him. Boris helped her escape to freedom, his superiors never knew about his involvement. Tia and Boris eventually reunite at a hotel in Vladivostok, later they share a moment of intimacy in a hotel room. Tia asks him about her song, Boris, encouraged to tell the truth, concedes that Alexei did weaponize her song after he performed the lobotomy and that he could not do anything to prevent him. Unfortunately, this prompts Tia to asphyxiate him.
Alexei is one of the scientists among the staff assigned to studying Tia, he performed many experiments on her: he took away Tia's child as she was in labor, then he performed the trans-orbital lobotomy which robbed Tia of her Siren Song. After Tia escaped (with Boris' help) his superiors suspected that he was the one responsible, as a consequence he was placed under heavy surveillance and ordered to work 20 hours a day. Alexei used this time productively to weaponize Tia's song which was subsequently used to kill all the employees at the municipal office in Ternipol, Ukraine.
|“||Humans need to possess things. We don't.||”|
|— Tia to Ryn|
|“||We are the most evolved species on the planet. We were born here to protect the Earth. That cannot be left in the hands of humans.||”|
|— Tia persuading Ryn to follow|
|“||"I know much more about them than you do. They're ignorant, thoughtless, self-absorbed. It's the very nature of being human."||”|
|— Tia telling Ryn her point of view|
|“||"You know nothing about it. I will put an end to these humans once and for all. And to you if you interfere."||”|
|— Tia before departing to the water|
|“||We shall not fight other tribes. We will unite them. But those who stand in our way... will fall.||”|
|— Tia communicating with her tribe|
|“||You, belong with us. Your blood is our blood. We are strong, and powerful. We are family.||”|
|— Tia to Katrina, convincing her to return to her true colony|
|“||That's mine. They made my song a weapon.||”|
|“||You were the only one who cared.||”|
|— Tia to Boris|
|“||There is no greater pain than a mother losing her baby.||”|
|— Tia to Hope|
|“||Your negligent disregard for this planet will no longer be tolerated. You were warned and now will suffer the consequences. The reckoning has come. Humans are the only species who refuse to take responsibility for their contemptible actions. War, famine, global warming. The time of judgement has come.||”|
|— Tia's manifesto to the humans|
Skills and Abilities
Tia demonstrates her skills and knowledge that she acquired from her Russian captors.
- Driving: She breaks into a car and uses a screwdriver to start the ignition, she is the second mermaid to have learned how to operate a vehicle after Ryn.
- Advanced Combat: Tia is a skilled fighter. This is demonstrated in her fight against Ryn; she managed to injure her with one strike to her chest.
- Craftsmanship: In "Survivor", she duels the current matriarch of her former mermaid clan with spears, she has modified hers with a spring-loaded mechanism. With the push of a button, the spear extends in melee combat piercing the opponent with the arrowhead.
- Tactics with Munitions: In "Northern Exposure" she acquires a crate of explosives, she sinks three fishing ships and then destroys the echo chamber of Ryn's colony with them. These explosives have Russian letters on them, this means that she has a arsenal of weaponry that originally belonged to her captors.
- Usage of Computers: "Til Death Do Us Part" is when we learn her skills in computers, she accesses Boris' laptop and uploads the audio file of her Siren song onto a separate flash drive. She further demonstrates them in "A Voice in the Dark" when she uses an emergency cellular notification network to transmit the recording of her Siren Song not only to everybody's cellphones in Bristol Cove, but to the rest of the Pruitt County. "The Toll of the Sea" is when she spreads it further, to the rest of the Pacific Northwest. In the same episode, she broadcasts a recorded manifesto to everyone in the world in many languages.
- She's the first known mermaid who speaks sophisticated English. The second Merfolk is Robb Wellens.
- Furthermore, she is fluent in 6 other languages.
- She takes up the name of Tia as a short name for the primordial Babylonian sea goddess, Tiamat, who tried to take revenge on the gods for killing her husband, Apsu, the primordial freshwater god.
- We learn in "The Toll of the Sea" that she was pregnant with a child, very close to giving birth, at the same time she was captured by the Russian government. Her child was then be taken from her.
- The merman she mated with is yet to be known.
- "Life and Death"
- "Mommy and Me"
- "The Island"
- "Northern Exposure"
- "Til Death Do Us Part"
- "A Voice in the Dark"
- "The Toll of the Sea"