Ape who guards the balance
Neferpitou has the appearance of a humanoid cat with wavy white hair. Their cat-like ears and tail are covered with yellow and white fur, respectively. They have ruby-red eyes, and their knees have demarcated joints like insect legs. Neferpitou's hands are slightly bigger than an average human hand for their size. Their clothes are a blue overcoat with six yellow buttons and cufflinks, shorts and orange socks with thin black stripes, and a pair of blue shoes.
Neferpitou is very loyal to the King, just like the rest of the Royal Guards and would sacrifice themselves for him. Neferpitou gets distracted easily, loves to play a lot and that makes them the most curious of the three Royal Guards. Hence their cat-like appearance, Pitou is a cat Chimera Ant who loves to play with their opponents like a cat would with their prey. Despite their cheerful and playful manner, Pitou has a sadistic and terrifying personality as well.
Unlike Menthuthuyoupi and Shaiapouf, Neferpitou does not seem to mind much in regards to Meruem's later newfound interests with Komugi. Thus, among the three Royal Guards, Neferpitou is the only one that greatly prioritizes Komugi's safety as opposed to how Menthuthuyoupi and Shaiapouf hate Komugi, something Neferpitou is aware of which creates distrust in regards to the matter, for making their king deviate from the path they envision for him.
Neferpitou is the first of the three Royal Guards born for the Chimera Ant King.  Pitou is also personally named by the Queen,  as are the rest of the Royal Guards. Pitou, similarly to the other Royal Guards, has no memories of their previous life.
Chimera Ant arc
Neferpitou is born.
Neferpitou first appears when Rammot and Peggy look for the missing rare prey, Pokkle. in the Chimera Ant nest in NGL. Rammot, having acquired Nen after being attacked with it, suddenly feels Neferpitou's frightening aura. Pitou enters the room and smells life hidden under a pile of bones, discovering Pokkle.  Pokkle is manipulated by Neferpitou and teaches the Chimera Ants about Nen and water divination ; afterwards, he is brutally killed and fed to the Queen. 
A victorious Neferpitou carrying Kite's head soon after their fight.
Neferpitou discovers that they are a Specialist and exits the nest to find out the extent of their new found powers. Meanwhile, Kite , Killua. and Gon have made their way to the Chimera Ant nest and plan on killing the Queen before she gives birth to the King. Kite feels a powerful En. Kite then understands the depths of the dark aura coming from Neferpitou. He tells Gon and Killua to run, but Neferpitou has already located the trio and slashes off Kite's arm in an instant. Gon quickly unleashes his aura after seeing Kite's arm ripped off, but Killua knocks him unconscious and runs away with him.  Neferpitou battles and kills Kite,  having enjoyed the match, decides to re-animate Kite's dead body as one of their puppets so they can enjoy another fight  and the other Chimera Ants have something to try with. 
Pitou forming their Hatsu.
The Queen is mutilated during the birth of the King, who then leaves with all three Royal Guards.  Some of the remaining Chimera Ants flee NGL and start their own independent lives.  Neferpitou assists the King in overthrowing the government of the Republic of East Gorteau. Under the guise of the former king of the Republic, Ming Jol-ik, the Chimera Ant King initiates the process of forcibly awakening Nen in the civilians of East Gorteau in order to form his own personal army to conquer the world—resulting in the deaths of millions unable to awaken Nen.  As Ants formerly under the Queen's rule rejoin the King, the Hunters Association mobilizes quickly to stop the oncoming genocide by sending in an Extermination Team of Hunters to East Gorteau. 
Residing in the East Gorteau palace, Neferpitou uses their Nen ability to manipulate hundreds of soldiers in the capital city of Peijin to rally citizens together. Their plans are thwarted by Killua, Knov. and Morel. As the day of the selection finally occurs, the Extermination Team attacks the palace and causes massive damage.  The King's consort, Komugi. is mortally wounded and under the King's orders, Neferpitou heals her.  Gon, however, threatens to kill Komugi unless Neferpitou agrees to restore Kite following the woman's treatment.  Though a promise was made to go with Gon to Peijin to restore Kite, once they've reached the area, Neferpitou affirms that it is impossible  and subsequently prepares to kill Gon. Gon then forcibly ages his body through sacrificing nearly all of his aura and kills Neferpitou in battle. 
However, Neferpitou's loyalty and devotion to the King was so great that even after their death, Neferpitou's nen still remained; their Terpsichora, even stronger than before, manipulated the corpse and attacked Gon. Gon, believing that Neferpitou is dead, is attacked by Neferpitou's corpse and loses an arm. Gon then pins Neferpitou to the ground with the arm he lost, and uses one final attack against Neferpitou, apparently destroying Neferpitou's body.  However, their corpse is later shown abandoned in the woods, probably with Terpsichora
Abilities & Powers
As one of the three members of the Royal Guard, Neferpitou is one of the most powerful Chimera Ants to live, and one of the strongest characters in the series. Neferpitou fought and killed Kite while suffering only minor injuries, having just discovered Nen.  Meruem also commented on Neferpitou's strength, after failing to kill them with one of his tail strikes, leaving them with only minor bruises.  Shaiapouf. another Royal Guard member, was driven through a wall by the same attack, although the king had increased his power at that time. The Hunter Association's Chairman Netero. considered the world's strongest Hunter during his prime, wondered if Pitou was more powerful than him,  as Colt. after witnessing both fighters' aura, reckoned. Gon and Killua were completely frightened by the extension and malice of their aura during their first encounter, and the latter stated that Hisoka and Illumi's, two extremely skilled and evil Nen users in their own right, were incomparable to theirs. Owing to their feline lineage, they have enhanced senses: their sight, hearing and smell surpass a human's many-fold. They have also inherited very accurate instincts.
Immense Sight: Pitou was able to spot Kite, Gon and Killua, who were around more than half a kilometer away. They even caught sight of Netero, who completely turned off his aura in the storm of Zeno's transmuted Dragons, although this was also achieved through his highly developed instinct. They also spotted Morel's Deep Purple Smoke Troopers many kilometers away.
Enhanced Hearing: Neferpitou heard their cell phone that was on low volume with their extremely accurate hearing.
Enhanced Smell: Neferpitou was able to smell Pokkle while the latter was hiding in a massive pile of bones.
Immense Strength: Neferpitou can rip off human limbs and heads without strain and with just one hand. Their legs are so powerful that they can cover distances of more than half a kilometer with just one leap. They can also pounce off the air with their incredibly strong legs and rush to the King's side.
Immense Speed and Reflexes: Neferpitou reached Kite's party, who was very far away from them, as soon as they entered their En. Neferpitou's reactions are also top-notch, as they could catch a glimpse of Netero's hands moving whilst he was preparing his Hyakushiki Kannon. They were also able to leap to Meruem from pressing off the air with extreme speed.
Immense Agility: Neferpitou can move very deftly and attack from any angle.
Immense Durability: Neferpitou withstood a blow of Netero's Hyakushiki Kannon without wounds. Also, their tail remained intact after Doctor Blythe to stop their movement. More remarkably, a grown, empowered Gon needed to use his Jajanken: Rock several times before finally managing to crush their skull. They also withstood a powerful strike of Meruem's tail with the intention to kill it.
Immense Resistance to Pain: Neferpitou was seemingly unaffected by one of Hyakushiki Kannon's palm strikes and hardly flinched when they broke their own arm, offering to injure itself more if they could prevent Gon from interrupting Komugi's treatment. They also withstood Gon's punches without getting stunned and while trying to fight back.
High Intelligence: Neferpitou's strength doesn't require them to think too much in a battle. Still, Neferpitou is very good at analyzing people and reading their feelings, and can understand the power of the humans they kill in order to select the ones to resurrect as puppets. Neferpitou has highly developed instincts which often lead them to make the correct choice. They are a very fast learner, as they mastered Nen in an unprecedented short time. Additionally, they learned how the human brain works and guessed how to manipulate it after reading just one anatomy book.
Proficient Hand to Hand Combatant: Thanks to their heightened physical capabilities, Neferpitou is an excellent brawler. They only have to use their on claws to dispatch their enemies, and Neferpitou's fighting style makes full use of their remarkable strength, speed, agility, balance and flexibility.
Neferpitou's terrorizing aura.
Even before learning Nen, Neferpitou was still able to greatly scare Rammot with their great aura, and Gon, Killua and Kite shortly after.
Together with the rest of the Royal Guard and the King, they are one of the fastest to learn Nen, accomplishing this feat without help. Their aura is so abundant that they can keep their dreadful En and puppets active for hours and not get tired in the very least. When Neferpitou first used Doctor Blythe, they were just imagining how to bring Kite back to life in order to fight him again: their powers are so great, they only needed to think of an ability to make it happen. Their Terpsichora can manifest in just a tenth of a second despite their strength. Due to their boundless devotion to the King, Neferpitou's abilities can increase drastically if they sense danger. Not even death and the destruction of their brain could stop them from attacking Gon, who they still sensed as a threat, with a more powerful than ever Terpsichora.
Their En is the widest shown so far. It is irregularly shaped: rather than a sphere, it takes the form of tendrils, a single one of which can be extended up to two kilometers in length.Source: hunterxhunter.wikia.com