The Akatsuki is a group of S-Ranked criminals who have betrayed their villages. They are banded together with the sole purpose of hoping to achieve world domination. The Akatsuki is composed of 10 members. There is no known criteria to be a member, but all members are extremely powerful and some of the most dangerous people in the series. Akatsuki members travel in pairs, with one member complementing the abilities of the other.
Akatsuki members all wear a dark black cloak with red clouds on it. The cloak also has a collar that fully covers the neck of the individual. Members also have nail polish on their fingernails and toenails. They also wear forehead protectors from their respective villages with the symbols crossed out. Each Akatsuki member also wears an unique ring. Each ring bears some sort of special significance that is unknown at this point.
Below are some information about the known members of the Akatsuki. Do not read below if you do not want to be spoiled!
Deidara - A Missing-nin from the Hidden Rock Village, Deidara is a part of the Akatsuki duo that comes to the Hidden Sand Village to kidnap Gaara. A very skilled and stylish warrior with special mouths in the palm of each hand, Deidara is able to manipulate clay into either a flight-capable clay bird that can support him or a huge bomb that is capable to leveling an entire village in seconds. He can do this all without a single exploding tag. Deidara is teamed with Sasori, whom Deidara refers to as Sasori no Danna (Master Sasori). This is probably because Deidara has a lot of respect for his fellow artist and because Sasori is, as Deidara says, a lot stronger than he is. But even though Deidara calls Sasori "Sasori no Danna", they still argue between each other quite often. Though most of the argument is about what is art. Deidara thinks art is something that dissappears quickly. Sasori thinks art is something that lasts a long time. During his fight with Gaara, his left arm gets mangled by Gaara's Sabaku Kyu (The Coffin of Crushing Sand), but he still manages to defeat him. Deidara loses his right arm to Hatake Kakashi when Kakashi used his newly obtained Mangekyou Sharingan against him. As a last resort, Deidara blew up one of his Buunshin in an attempt to kill everyone else around him. However, his Buunshin was teleported away from the scene by Kakashi. Later Deidara was defeted by Sasuke and blew up his entire body.
Hoshigaki Kisame - Along with Uchiha Itachi, he attempted to kidnap Uzumaki Naruto for Akatsuki purposes several years ago. Kisame and his sword, the Samehada "Shark Skin" both have features that resemble a shark. Kasami's sword also has the ability to drain others' chakra. Kisame comes from Hidden Mist Village. He is also known as the mysterious one of the Hidden Mist (Kirigakure no Kaijin). He is also part of the Kiri no Shinobigatana Nanajin Shu ("Seven Swordsmen of the Mist"), as was Momochi Zabuza, famed for their usage of oversized swords. Kisame's chakra is apparently considered very large, even by Akatsuki standards.
Hidan - Hidan bears a large rope scythe and admits to be the slowest attacker of the group. The village he comes from is unknown. He and his partner Kakuzu were responsible for acquiring the Two-Tailed Jinchuuriki. Hidan practices an evil god cult religion named Jashin. This religion loves chaos and death. Hidan himself is almost compeletly immortal. On one of Kakuzu's side bounty trips, he killed Sarutobi Asuma in battle using some unknown jutsu which allows damage to himself to be felt by his opponent. He was eventually blown up and buried deep underground by Shikamaru.
Kakuzu - Kakuzu is a missing-nin from the Hidden Waterfall Village. He was a bounty hunter who often got sidetracked. His body was stitched together by strange tendrils which he used to rip out the hearts of his opponents and then insert into his own body. This granted him their elemental affinities in the form of masked tendril entities. Along with his own Water affinity, he had access to Wind, Fire, Earth and Lightning attacks. Kakashi destroyed the Earth heart, Hidan accidentally destroyed the Water, and Naruto destroyed Wind and Fire hearts. Kakuzu then gets killed by Kakashi after losing his hearts.
Konan - Konan is the lone female member of the group. She works alongside Pain. This duo secretly reports to Tobi and seem to be the only ones who know about his true nature. Konan possesses the ability to disperse her body into paper, which can then fold itself into butterflies for tracking purposes. When she was younger, she, Pain, and another orphan were trained by Jiraiya for a short period. Jiraiya helped them become stronger and able to fend for themselves in the war torn Rain Country.
Zetsu - At the moment, not much is known about Zetsu. His head appears to be enveloped in a large venus flytrap. The right side of his face, and likely his body, is black in color while his left side is white. His pupil-less eyes and superior vision suggest that he may harbor something similar to Byakugan. His first appears after the Naruto and Sasuke fight, which he observed secretly. He is responsible for warning the Akatsuki of the positions of the approaching Team Kakashi and Team Gai during their extraction of Gaara's bijuu. He has the ability to merge with trees and other plants. Zetsu is a Missing-nin from the Hidden Grass Village. He seems to have a split personality, as the white half of his face speaks only in Katakana, which could indicate a robotic voice, while the black side uses both Kanji and Kana. He is also a cannibal, eating Kisame's body substitute, which fits his "venus flytrap" body.
Orochimaru - After failing to become the Fourth Hokage, Orochimaru began to study forbidden jutsus. After leaving the village he joined the Akatsuki and partnered with Sasori during this period of time. Orochimaru coveted Uchiha Itachi's Sharingan. He tried to take Itachi's body but Itachi bound Orochimaru with a Genjutsu and cut off his arm. Orochimaru fled and took his ring with him. He eventually formed the Hidden Sound Village and trained Uchiha Sasuke. When he tried to take over Sasuke's body, but Sasuke traps him with his Genjutsu and suppresses him. Orochimaru's underling Kabuto inserts some of Orochimaru's flesh into his body, which soon exerted its own will by gradually taking over his body.
Sasori - Sasori traveled with Deidara from the Hidden Rock Village. He was a legendary puppet master from the Hidden Sand who left his village approximately 20 years before the start of the series. Sasori converted portions of his body into puppet parts, retaining a flesh and blood portion of his original self in a chest container. He uses human puppets which only he knows how to do. He died in battle with Chiyo and Sakura.
Tobi - Tobi was initially seen as an associate of Zetsu. He appeared clumsy but was very polite in his speech. He eventually succeeded in becoming a member and took over Sasori's position in the group. He was partnered with Deidara. After Deidara's death, Tobi gave orders to Pain about the actions of the group. He is revealed to possess the Sharingan and claims to be Uchiha Madara.
Uchiha Itachi - Noted within the Wanted Book, Uchiha Itachi is an S-Level criminal and a Konoha Missing-nin. At age 7m he graduated as the top of his class; By 8, he mastered the Sharingan; He became a Chuunin at age 10; And at 13, he became an ANBU Captain. Uchiha Itachi became so powerful that he was feared by Orochimaru at age 18. He left Konoha after becoming power-hungry and destroying his village. He killed everyone but his brother Sasuke. We later find out Itachi might have wanted Sasuke alive to be killed by him, seeing as they could both use the Mangekyou.
Pain - Pain acts as the leader of the group, though he and Konan secretly report to Tobi. He has been adamant that the group can fulfill their desires if they finally possess the bijuus. He also was responsible for summoning the huge statue which holds the spirits of the bijuus withdrawn from the Jinchuurikis. Pain is very calm and tries to bring order to the group. It has been said that he's never lost a battle. He also possess the Rinnegan, an extremely rare and powerful Doujutsu that only he is known to possess. Not much is known about Pain but when he was younger other than he was called Nagato. He was trained by Jiraiya for a short time with two of his friends, one of them being Konan.