Karai (TMNT 2012)

Oroku Karai (born Hamato Miwa) is one of the main protagonist in Teenage Mutant Ninja Turtles. She was originally the biological daughter of Splinter. Now, she is a 16-year-old master Kunoichi, adopted into The Foot Clan by Shredder as his daughter until her discovery of her true heritage in The Hamato Clan and the Ninja Turtles. She made her debut in the episode New Girl In Town. She was mutated into a serpent in Vengeance is Mine. She was successfully turned back into a human but was brainwashed to be loyal to the Foot Clan in The Deadly Venom. She threw up the brain worm in The Fourfold Trap.

Official Description
"I am Karai, daughter of Shredder and only Kunoichi of the Foot Clan. For my entire life I was taught to hate Splinter, the being responsible for my mother's death...or so I thought. Now things are not what they seem and I can't tell from friend or foe. Well, so much has changed since I found out that Shredder deceived me and took me from Splinter, my real father. Shredder kidnapped me, but I was saved by the turtles and taken home. Being reunited with my real family wasn't enough-I have to have my revenge...deadly revenge. Now things will never be the same."

- Karai

History
Born in 1996 to Hamato Yoshi and Tang Shen, Hamato Miwa and her family once lived in complete harmony until Yoshi's adoptive brother Oroku Saki made an attack on their home in the middle of the night and sought to battle Yoshi to the death. Some flaming candles were struck with a clawed-weapon and the fight caused a fire to break out, killing Tang Shen in the process. Yoshi had thought Miwa had died in the fire as well, but unbeknownst to him, for revenge purposes, Saki had kidnapped her, feeling he should take something from his former friend since hetook something from him; the love of Tang Shen. Since then, Saki, renamed in his birth clan as the Shredder, had renamed her Karai, raised her as his very own daughter, trained her in the ways of Ninjutsu, and fed her tons of lies about what happened to Tang Shen. Presumably, one of these lies was that he and Tang Shen were the ones together and that it was Splinter who caused the immense fire. However, as the love interest of Leonardo, she discovered her true heritage in the Hamato Clan and got mutated into a serpent while facing Shredder alone.

Appearance
As a human: Karai is Donatello's height (approximately) and is quite slender. She has short, dark black hair with a large portion of it dyed blond in the back. She wears bright red eyeliner over the tips of her eyebrows, and often wears a distinctive black and silver armored ninja outfit. When she chose not to wear her ordinary outfit, however, she instead wore a brown biker jacket with metal studs all over it. She also wore blue jeans.

As a mutant: She is a snake armed white serpent with green eyes, snake heads that replace her hands, and armor that has become infused with her skin.

Personality
Unlike her previous incarnations, Karai is portrayed as a rebellious teenager. She always seems to enjoy having the freedom to make her own mistakes and cause trouble. Karai can be serious when needed to be and occasionally desires to know what is going on in her surroundings before making a move that she herself or her former clan could later regret. This can be noted numerous times, such as when she encountered the Kraang and decided to work briefly alongside the Turtles to slay several of the robots.

She has now discovered the truth about her real family and she has apparently "changed sides". 

Karai also seems to have a soft spot for people that have lost their mother, as seen in "Karai's Vendetta", where she hesitated to harm April when the latter leaked that she lost her own mother.

Even when she believed Shredder was her father, she rarely wanted to harm anyone; she was simply Shredder's puppet, but she had no clue.

Karai/Miwa seems to be strong, rebellious and fearless, but she is actually quite kind and compassionate and likable.

After being turned into a mutant snake, Karai becomes feral and predatory, but retains enough of her personality to briefly recognize Splinter and not only call him "Father", but at Season 2's end, save him from drowning after he is thrown down the sewer by the Shredder. As a sign of their connection, she also managed to fight her instincts enough to not only recognize and call Leo by his name, but also beg him to help her. Despite this, Karai also feels that she is becoming dangerous and wants to stay away from the turtles.

Powers and Abilities
Ninjutsu: Her skills as a Kunoichi are very formidable, as she is easily able to take on Leonardo one-on-one or all four of the turtles at once, which can be seen in Enemy of My Enemy. Her primary weapon of choice was a Tanto, which is a short and sharp Japanese blade.

Acrobatics: Though she being human showed some strength against her enemies. Having great acrobatics to compare to an athlete person.

Snake Form
Venom Spit: She also have the power to spit blinding venom whenever she is angered. She can also use her tongue in a pitch fork like action.

Retractable Teeth: It's also shown that her sharp teeth are retractable.

Second Mouth: In the back of her head, there is actually a second mouth. When she shows it, her metal scalp and the area under that will split apart. This second mouth has a snake tongue and teeth, just like her actual mouth. However, it is never shown to have four main fangs in the front like the latter. It is unknown if she can use this to eat/drink or use vocal cords, but this mouth has tremendous grip strength as she bit down on a Kraangdroid's arm with it then ripped the arm free just by pulling.

Enhanced Strength: She has incredibly fast reflexes, an amazingly strong tail that can be used for whipping, constricting or a able to smothering.

Aquatic: Like most snakes she can swim for long periods of time as she was traveling to another location from the West Side of New York.

Weaponry: Her weaponry is notably sharp teeth and long tail.

Metamorphosis: She is also shown to be able to morph between her human and mutant form but even as a "human", a few of her snake features can still be noticed. In "The Fourfold Trap", it's revealed that she can actually revert to her human form that she had before she was mutated that has no serpentine characteristics.

Intelligence and Communication: She shown to have her intelligence as human but loses a bit of it from becoming more bestial mentally while in mutant form. She can still hiss while talking, but that has some difficulties. Though her mind is fixed by "The Deadly Venom."

Healing Power: She also has the ability to heal her skin wounds (such as severe burns), she just has to shedd her skin to her mutant form and when it goes back to human, the wounds completely disappear.

Trivia

 * The name "Karai" is the same name as the Japanese adjective karai that generally translates into "spicy" (for describing foods), but also covers less common meanings like "severe" or "harsh". It also resembles words like kurai meaning "dark", and kerai, a word for retainers who serve under a lord or clan.
 * Like Shredder, Karai was raised by the opposing clan. Karai was born into the Hamato Clan but taken by Shredder and raised by the Foot Clan. This is mirroring Shredder's story how he was born into the Foot Clan but raised by the Hamato Clan.