Donatello 2012

Physical appearance
Donnie is a mutated anthropomorphic teen ninjutsu turtle warrior with brownish green skin. Unlike all his previous incarnations, this newer, updated version of Donnie has a gap between his teeth in addition to having a much taller and skinnier body shape with brown/red eyes, but like his brothers when they're in combat or being stealthy, he has whited-out eyes (like the 2003 incarnations).

Just like most incarnations, he wears a purple mask where the tails of the mask are longer than any of his brothers, except for Raph's. His ninja gear consists of brown knee and elbow pads, light brown bandages wrapped around his ankles, wrists and white bandages wrapped around his fingers.

Personality
Donatello is incredibly book smart. He is incredibly skilled, having "a way with machines". He is a pro scientist, mechanist, and mathematician. He devotes more of his time to studying technology, biology, physics, chemistry, mathematics, metallurgy, and eventually astronomy (as of Season 4) over ninjutsu. He invents a lot of machines and gadgets that are often helpful in battles.

Although he is a skilled martial artist, he often puts more faith in his high-tech gadgets and machinery than listening to more spiritual advice with traditional ninjutsu methods taught to him by Master Splinter. Despite his genius-IQ level, Donnie often tends to over-analyze, overthink, and over-complicate things (especially Splinter's advice), ultimately putting too much of a burden on himself and making bad decisions. However he believes in science and is over-reliant on modern tech-gadgets rather than spiritual and religious tactics.

Donatello is loving and romantic. He has a crush on April and it’s very hard to talk to her at times. April frequently kisses him at times (first seen in "Target: April O'Neil"). His friend and rival, Casey Jones, also has a crush on April and it often causes tension between the pair (though it's much less after "Race with the Demon").

Donnie is also very nerdy and socially awkward which causes his brothers (especially Raphael) to mock him. Sometimes, Casey does this as well. Overall, he gets nervous in social situations. Communication also causes problems. When he tries to explain his invention or part of a plan to the team, the team would not understand what he’s saying, which could get frustrating at times.

Despite Donnie’s smarts, he can be high-strung. He hates being rushed by his brothers, especially Leo or Raph in certain situations. This would get him easily annoyed as he would snap at his older brothers when they nag him to go faster.

Donnie is tense under pressure. When something goes wrong, especially with his gadgets and technology, he will snap. Donnie has picked up some of Raph’s bad temper, although Donnie is not as angry and violent as Raph. Donnie can get frustrated a lot and become argumentative, especially when his intellect is challenged (though ironically with Fugitoid, they both get along really well). Donnie would often lash out at Mikey whenever he messes with his inventions and technology, but it's often verbal rather than physical. Despite this, Donnie is overall a compassionate character and would support his family and allies anytime.

Skills, powers and abilities
Mutant physiology: As a mutant, the Mutagen Ooze heightened Donatello's physical attributes to considerable extraordinary levels. He possesses strength, speed, reflexes, agility, endurance, recovery speed, and stamina much greater than even the finest human specimen athlete. His mutant abilities has been listed as shown below:
Enhanced strength: Donatello possesses an adequate level of strength. He and his brothers have been mutated and have had years of training under a grand master of martial arts, so their strength has been amplified as a result. In "The Pulverizer Returns!", Donatello overpowered the Foot Clan humans with no difficulty.
Enhanced speed: Despite being a turtle, he is not slow. Donatello is able to move at great speed, able to free run on rooftops without losing momentum. He can also move things at enhanced speeds too, such as twirling his bō staff. He can also spin his staff at incredible speed to momentum to his strikes.
Enhanced reflexes: Donatello also possesses great reaction speed, allowing him to dodge projectiles such as lasers the Kraang's blasters, and enemy attacks. He can run fast enough to avoid laser fire from a Kraang weapon. In "Rise of the Turtles", Donatello was able to dodge laser fire from Snake's weapon designed by Kraang at very close-range.
Enhanced agility: Donatello can coordinate his bodily to levels that are beyond then the finest human athlete. In "New Friend, Old Enemy", he has shown to acrobatic flips from one building to another building at further distance.
Enhanced healing: Donatello can heal faster than normal humans. He was able to take numerous hits from mutants like Dr. Tyler Rockwell, Dogpound and Slash, seriously injuring himself and was still able to fight. He also was able to fight Shredder, but was hurt by him. In "Slash and Destroy", Donatello healed from severe injuries including his sprained arm from Slash's brute attacks in several days.
Enhanced Stamina: Due to his ninjutsu training, Donatello has high-level stamina , which allows him to keep up with his training. A good exhibition of his enhanced stamina is when Donatello is training the Pulverizer.
Enhanced endurance: Donatello has high-level endurance and can take hits better than Mikey can take, but not as good when compared to Leo and Raph.
Retractable Limbs into Shell: Donatello has the normal ability of a turtle to get into his shell.
Semi-aquatic adaptations: He is able to swim long distances, dive deeply and hold his breath underwater for a long time.
Super intelligence and communication: Donatello is a extreme scientific genius in multiple fields. He is able to invent impressive machines, including, but not limited to, the Shellraiser, T-Phone, Metalhead, Ninja Smoke Bombs, Turtle Racer, and Turtle Blimp, all out of trash found in junkyards, garbage dumps, etc. He is also an master biologist, chemist, and geneticist, as he was able to create the first ever successful Retro-Mutagen and has often been seen in his lab experimenting with chemicals. Additionally, Donatello is able to plan out strategies, as well as build, fix, take apart, and hack into machines. His super intelligence is also his greatest advantage in battle. In "Follow the Leader", it is revealed that Donatello is able to use impressively quick logical thinking and mathematical calculations while in combat. For example, he is able throw shuriken at nearby objects and/or surfaces, in order to make them bounce off objects again and again in the exact directions he predicted and calculated previously. He is incredibly intelligent able to calculate complex equations in his head, create different machines and handle the creation of medicines and other chemical compounds. He enjoys tinkering with items he finds in the junkyards and in the abandoned part of the sewers, which have allowed him to make the Shellraiser, the T-phone and T-pod. Although Donatello is not a great tactician like his brother, Leonardo; however, he can assist Leonardo in difficult situations and complex missions. Touched by his father as human given the power to speak and understand perfectly human English. Furthermore, Donatello's super intelligence is so great that he created many tech machines throughout his career, such as Turtle Mech, Turtle Flyers, Metalhead, Patrol Buggy, Turtle Sub, Shellraiser, and many others. One of the greatest testaments of his super intellect was when Donatello repaired Fugitoid's damaged robotic body, a feat that was considered to be impossible. Even as a baby, Donatello exhibited high levels of intelligence for his age. Such as putting together a camera and plugging in a lamp. Splinter even referred to Baby Donnie as the smart turtle before giving him a proper name.
"Slowly. Keep your hands near your center and switch sides. Smooth. Fluid, right?"
— Donatello to The Pulverizer.

Bōjutsu: Donatello was trained by Splinter in the use of the bō staff, in which he twirls, swings and stabs like a spear. As Donnie's fighting relies more on defense than offense, he makes use of his bō's versatile nature to block as well as counter attack. Despite this, he also able to deliver powerful strikes that can send enemies flying, and combine it with his physical combat skills.
Naginatajutsu: Donatello skills with his bō staff translate to his proficiency with the naginata. His staff possesses a retractable blade that is mostly used in cases when he is fighting robots.
Shurikenjutsu: Donatello can throw shuriken with remarkable accuracy and even make calculations to have them bounce off surfaces and strikes multiple enemies.
Tantōjutsu: In "Mousers Attack!," Donatello threw a tantō to take April's phone out of Dogpound's grip.
Weaponry: Donatello is proficient in various types of weapons. In The Pulverizer Returns!, Donatello learned to adapt his surroundings and shown to use other non-weapons, such as a broom to fight Dogpound and the Foot Clan.
Expert martial artist: Donatello is an excellent fighter. In "Monkey Brains", he was taught by Splinter to fight without using his head, as he defeated Victor Falco without thinking in unarmed combat. He also taught his 1987 counterpart in how to improve his combat skills in "Wanted: Bebop & Rocksteady".
Master of stealth: Being taught by Splinter, Donatello, as well as his brothers, are able to be one with darkness and hide and move within the shadows without being noticed. Like his brothers, he is stealthy, can hide in the shadows, sneak around without being detected, and use hand to hand combat.
Biography
Fifteen years before "Rise of the Turtles, Part 1", Donatello and his brothers were once ordinary turtles; when they were infants the benevolent Hamato Yoshi purchased the four as pets. When their soon-to-be father walked passed a strange man, he felt something odd about him and followed. Unfortunately Yoshi gave away his position when he accidentally stepped on a brown rat's tail. The Kraang found him and attempted to kill him, but Yoshi fought back hard. During the scuffle, the aliens dropped a container of mutagen, Yoshi, having to have stepped on that rat, thus mutated into a humanoid brown rat by the name of "Splinter", While Donnie and his brothers, after having been in contact with Yoshi and the clerk of the pet store where they were bought, mutated into humanoid turtles. Yoshi raised the turtles as his own children and to train them in Ninjutsu.

Splinter knew they would never be accepted in society and with the Kraang hot on his trail, the five of them lived in an abandoned water tower and a warehouse avoiding detection. During all of these trials, Splinter and the Turtles bonded and after he noticed the baby turtles trying to copy his Ninjitsu training, Splinter decided that there was an opportunity to turn this new life he was thrust into to his advantage, Taking one of his favorite books about the Renaissance art named them after the Artists he admired the most.

After last fight against the Kraang in the sewers in Splinter overheard the Kraang talking about how it became impossible for them to track Splinter and the Turtles there, Splinter decided to remain there. Thus making it that Splinter had found the safe environment where he could raise his adopted sons. Knowing the world would be dangerous and there would be a time where they want to explore the outside world, Splinter started to train the boys in the art of Ninjitsu. Eventually giving Donatello his signature Bō staff "for a thoughtful soul and a peaceful heart."

Donatello's character design was also updated, giving him a gap in his teeth and a taller, more leaner appearance than his brothers.