Naraku's incarnations

To get rid of unnecessary parts as well as keeping a better eye on his surrounding situations, Naraku was constantly releasing detachments of himself to carry out his bidding. Only a few of the detachments truly live up to their purposes as most betrayed him or were quickly disposed of by the people going after him. As of Chapter 548, with the death of Byakuya, Naraku no longer has any detachments:

Kanna
Kanna is an albino girl that barely speaks. She is a demon of mu, "void" or embodisment of nothingness. Kanna comes from an old word meaning "godless world." She is Naraku's first detachment, and remains utterly loyal to him while knowing that they are just used as tools in his schemes. Representative of the void in which she controls, Kanna herself is completely devoid of any emotion, never questioning any orders given to her by Naraku. In chapter 480, after a failed attempt to destroy Inuyasha's Tessaiga, Naraku orders her to commit suicide by shattering herself—as a final attempt to destroy Inuyasha's group (In the anime he destroys her heart). In her final moments, however, Kanna seemed to display some signs of emotions, as if she really did not wish to die. It is in her death that she commits her only act of defiance to Naraku: As a shard of Kanna's shattered body flies into Kagome's eye, Kanna uses this opportunity to show Kagome the light that is present within the Shikon no Tama, which could be the key to defeating Naraku.

Kagura
Kagura is a powerful wind sorceress. She is the first of Naraku's detachments to appear in the manga and the anime, though by order of birth she is actually his second detachment. Naraku endlessly uses her as bait to test the enemies' strength and, aware of her betrayals, keeps good watch over her. Her storyline is constantly followed as she plots to destroy Naraku and win back her heart, often in combination with Sesshomaru, to whom she is attracted. Eventually, she is killed by Naraku after she openly betrays him to protect Kohaku.

Goshinki
The third detachment of Naraku, Goshinki was a large horned ogre with the ability to read minds. He was extremely agile, physically very powerful, and had teeth so strong they ultimately broke the Tessaiga. That, however, ended up being his own undoing. As happens whenever his sword is taken away from him in life-risking situations, InuYasha transformed into a full Yokai out of desperation and thus quickly defeated Goshinki. Following his death, Sesshomaru contracted Kaijinbō to create Tōkijin from the fangs of Goshinki head.

Jūrōmaru
He was a feral detachment and brother of Kagerōmaru, who lived in his stomach. He and his brother Kagerōmaru were both killed in battle by Inuyasha with Kaze no Kizu (Wind Scar).

Kagerōmaru
He was a small, fast and intelligent detachment from Naraku. He lived inside Juromaru. He was not particularly loyal to Naraku. He and his brother Juromaru were both killed in battle by Inuyasha with Kaze no Kizu (Wind Scar).

Un-named Yokai
An unknown Yokai was created by Naraku in chapter 174 in the manga. This was destroyed by the reincarnated Kikyo in the same chapter during her confrontation with Naraku.

Musō
Muso is the reincarnated Onigumo, Naraku's human kernel. Naraku dumped him in order to get rid of his feelings towards Kikyo, which Naraku felt impeded him from defeating her. Due to Onigumo's disfigurement, Muso was born faceless. He attacked scores of men until finding a face he found appropriate for himself. At first, he appears to have no memory, either of his life as a person, or as the human heart of the half-demon Naraku, who shut him off shortly after being born so as to avoid being overcome by Muso's human feelings. Muso recalls his memories during his fights with Inuyasha, remembering also of his attraction to Kikyo. He is ultimately reabsorbed by Naraku after a short time of independence. He demonstrated infuriatingly powerful regenerative abilities, able to piece himself back together even after taking the Wind Scar from Inuyasha. However, had Muso's heart been destroyed, not only his but Naraku's downfalls would have been assured. He also demonstrated the ability to shapeshift new limbs, spikes, multiple legs and arms, claws, and a tail.

Akago
He is a child with the ability to force other people into doing his bidding by manipulating the corruption within their hearts. He used his powers to track down the whereabouts of a Shikon no Tama shard. During his journey, Akago was cut in half by a priest's spiritual powers. The left half (which remained to be Akago) was taken by Kanna, whilst the right one (which became Hakudōshi) was put in charge of Kagura. He later is placed inside the haku (life force) puppet, Mōryōmaru, in a plan to make it so strong as to being capable of overthrowing Naraku. In Chapter 446, however, Naraku manages to absorb Mōryōmaru, and with it, the infant. In Chapter 448, Naraku disappears with Akago, and by his next appearance in Chapter 452, has reabsorbed him.

Hakudōshi
He is an incarnation from Akago. Hakudōshi literally means white child. Taking the form of a young child, he was able to tame the horse demon Entei. He continues Akago's quest to get the last Shikon shard. After Naraku is nearly destroyed at the boundary of the afterlife, Hakudōshi is charged with flushing out Kikyo. He eventually is found out as a traitor to Naraku and is sucked in by Miroku's Kazaana.

Byakuya
Naraku's incarnation that first appeared in Chapter 397. He was created to replace Kagura, serving the purpose of tracking down Mōryōmaru while keeping tabs on the full-extent of Inuyasha's Tessaiga. Byakuya uses origami as his primary weapon and seem to be able to create illusions, but not much else was known about him. He was killed when Inuyasha used the Cutting Meidou on him after he attacked Kagome.