Ninja

Ninja (or shinobis in the historical term) are Japanese covert assassins often for hire or belonging to a shady clan. They tend to specialize especially in stealth-oriented affairs such as sabotage or infiltration although they are able to competently fight head-to-head. Their counterparts are the battle-oriented 'samurai'.

Ninjas in the Mortal Kombat series
Ninja is a loosely used term in the actual sense of ninjas regarding the Mortal Kombat franchise, thus they are a very prominent group, featuring 15 characters listed under this classification. It is used as a classification to those who wear a colored uniform and mask to conceal their face. Save for two, all of the ninjas have debuted as secret characters, falling in line with their loose definition as they are associated with secrecy and stealth. Common attire is a broad vest that splits apart at the chest area in a V-formation as well as boots or 'tabi'. A short cloth is tapered at the waist area. The attire is completed by a mask to conceal their identity though some of the characters have often removed their masks for deadly purposes. It is not uncommon for a ninja to possess supernatural powers that gives them the edge over their opponents. From Mortal Kombat to Mortal Kombat Trilogy, ninjas were virtually identical to one another in terms of appearance, save for their color choices and powers. From Mortal Kombat 4 onwards, ninjas were given a better sense of diversity with their designs.

Male ninjas
them in after successfully landing a hit. He possesses control over hellfire.*Sub-Zero - The successor to his older brother. Sub-Zero is a member, and later, grandmaster of the Lin Kuei clan, an organization of Chinese warriors often mistaken for ninja due to grandmaster of the Lin Kuei clan, an organization of Chinese warriors often mistaken for ninja due to their garbs. Like most clan members, Sub-Zero dresses in blue. From Deception onwards, he wears armor plating with dragon markings adorned. True to his moniker, he has mastery over the element of ice using it a variety of defensive and offensive methods the demise of his family and clan. At first, he had thought to be the perpetrator until revealed himself at the most opportune moment. Scorpion then has made it his goal to kill Quan Chi, no matter what. Scorpion dresses in yellow shades with a skeletal theme to fit his dead status (e.g lower mask looking like a ribcage in MK vs. DCU). He wields a Spear weapon which he uses to fling at his opponent and reel
 * Scorpion - Perhaps the only character in the Mortal Kombat Universe who can actually be considered an actual ninja as he is the only known member of a Japanese ninja clan. Formerly known as Hanzo Hasashi, Scorpion is a specter who constantly rises from the dead to avenge
 * Reptile - Shang Tsung's former bodyguard one of the two lone survivors of the near-extinct Saurian race. He is constantly seeking a worthy master to whom he will serve, showing the utmost loyalty to them. He dresses in green and black garbs though because of his separation from his clan, he begins to resemble less and less like a ninja and more of a beast to the point where he doesn't even wear a mask. He possesses abilities inspired by several reptilian creatures.
 * Sub-Zero- one of the most popular characters in the Mortal Kombat series. There are in fact two incarnations of Sub-Zero, and they are siblings: older and younger. Both are blue garbed warriors that are brothers and members of the Lin Kuei that descended from Cryomancers: an Outworld race possessing the ability to generate and control the powers of ice, although both of them were born in Earthrealm. The younger one bears a scar on his right eye which he received from a fight with Kung Lao, in canonically-disputed Mortal Kombat: Shaolin Monks. However - as of Deception - the scar has faded away, possibly because of a side effect of his Dragon Medallion.
 * Ermac - A ghastly legion of warrior souls fused into one single entity, referring to themselves in the plural form instead of singular. Formerly a pawn of Shang Tsung, Kenshi frees Ermac and joins the side of good to atone for what he had done in the name of evil. Dresses in red with a certain warrior theme and wears a mask completely composed of black bandages. Has the power of telekinesis and a few soul-related powers
 * Rain - A self-proclaimed prince of Edenia and a son of Argus. An orphan who bore witness to the invasion of his home by Shao Kahn's Outworld forces. Once a minion of the ruthless emperor and a willingly traitor to his own realm, Rain fights for evil. Dresses in purple garbs with a royal theme. He possesses the ability to control the weather thanks to his half-god heritage, using water and lightning to drown his opponents in his might
 * Noob Saibot - The first man under the moniker of Sub-Zero and the current one's older brother. Killed by Scorpion, Sub-Zero plummeted into the Netherworld and became a wraith with no recollection of his past or morals as a human. Noob Saibot aims to further his goals of conquest with the help of Smoke's nano-technology to create an army of cyber-demons that will follow his command. Appears as a solid black with belts and a tight-fitting suit to fit in with his new-found assassin theme. Possesses the ability to meld with the shadows and phantom-themed powers to cripple his opponents
 * Classic Sub-Zero - Classic Sub-Zero was a playable character in Ultimate Mortal Kombat 3 and Mortal Kombat Trilogy, initially believed to be the live representation of the deceased original Sub-Zero. His biography screen is almost identical to the younger Sub-Zero's in Mortal Kombat II; it states that, though believed killed in the first Mortal Kombat, he is thought to have returned to try and assassinate Shang Tsung.
 * Smoke - A former Lin Kuei warrior who fell victim to, but overcame subjection of the roboticization process. Sub-Zero's closest friend and ally, Smoke has been reprogrammed by the older brother, Noob Saibot for his own ends. He can do naught but obey the evil wraith's commands. Wears silver and black armor. Possesses incredible speed and the ability to manipulate his intangible namesake for a variety of purposes.
 * Reiko - Reiko is a grim and stoic looking man with black and white hair, glowing blue eyes, and a penchant for brutality. He was originally introduced in a typical ninja archetype in Mortal Kombat 4. He also has a mask-like black tattoo over his eyes.Not much is known about him, savethat his primary occupation is that of a general.
 * Chameleon - An enigmatic warrior shrouded in mystery. His past and ambitions are unknown to all. Wears a quilted garb that changes colors periodically and transparent skin. Possesses powers based on the other male ninjas
 * Hydro - A friend, and fellow member of the Lin Kuei, of Sub-Zero. The water power ninja and foe of Scorpion, by whom he was later killed. Possesses powers based on water, as his name implies.
 * Tremor - Member of the Black Dragon, possible former member of the Lin Kuei, was defeated by Jax. Has the ability to create shockwaves in the ground much like Jax himself, and the ability to create 3D fireballs.
 * Wu Lae - the leader of the Tengu clan located in Arctika. He uses a scythe in battle. His clan is a rival to the nearby Lin Kuei, but the two share an uneasy truce in which the Tengu remain out of the Lin Kuei's territory.
 * Tekunin - Tekunin was a Japanese-born ninja who served as an assassin for the Lin Kuei clan many years ago. His practice in Japan eventually formed the Shirai Ryu clan, a tremendous rival to the Lin Kuei.
 * Komodai - Komodai was a male Saurian that invaded Earthrealm.It is not known where he originated from except that he was accompanied by a team of fellow Saurians that broke through a dimensional portal into Earthrealm where they fought the Defenders of the Realm.
 * Oniro - Oniro was a male Human and was the Grandmaster of the Lin Kuei before its reformation.It's not known how long Oniro held the title of Grandmaster except that he was present before the order was given to automate their ninja assassins. He was present when both Cyrax and Sektor went through the cybernetic process at which point both Sub-Zero and Smoke refused to take part in.
 * Yong Park - Yong Park was a former Lin Kuei ninja (the Lin Kuei are described as practicing the art of ninjitsu in the novel) turned toll-taker. He was killed by Sub-Zero twenty years later for leaving the clan, a traitorous act punishable by death. His soul merged with the body of his son Tsui Park to become Scorpion.

Cyber ninjas
It has never been clear as to how mechanical the automatons truly are. In Mortal Kombat 3, a damaged cyborg sparks and the skeleton is revealed. The skeleton is almost completely mechanical, aside from the rib cage and skull. The rest of the body is filled with odd mechanical parts and wires. This was about as complex as the cyborgs were at the time. In Mortal Kombat Gold, it was revealed that the cyborgs wore helmets and retained their faces underneath; Cyrax's alternate outfit and ending revealed this.
 * Cyrax - Cyrax was the second Lin Kuei warrior who was turned into a cyborg. However, Cyrax was captured by Sub-Zero, reprogrammed, and permanently malfunctioned. He was then captured by Sonya Blade and Jax Briggs, and was partially returned to his human state. In gratitude, Cyrax joined the Special Forces.
 * Sektor - Sektor was the first to undergo this process of roboticization, and he would prove to be their biggest success. The Lin Kuei programmed the cyborgs to do their bidding, and Sektor's main objective was to seek out and kill Sub-Zero, who left the clan after refusing to be transformed into a machine. Sektor was devoid of a soul, lost all human emotions, and has never succeeded in his mission.
 * Smoke (unit LK-7T2) was the third member of the clan to transform into a cyborg. After returning from a mission, he and Sub-Zero learned of the Lin Kuei's plans to transform their members into robots. The two fled; Sub-Zero escaped, but Smoke was captured and forced to become a cyborg. He was later captured in Outworld by Shao Kahn's army. Hopelessly imprisoned, he chose to shut himself down. Afterwards, Smoke was found by Noob Saibot and reactivated, along with some tampering of his machinery. The two would form a team called Noob-Smoke. As of now, Smoke is torn between serving his new master and searching for his lost humanity.
 * Hydro - He was a younger but close friend of Sub-Zero and journeyed with him to combat the forces of Outworld. His unique talents allowed him to manipulate water. His control over the element allowed him to blast strong waves of water at his enemies with freezing water that they actually froze his opponent upon contact.Hydro was killed by Scorpion in Outworld as part of the undead wraith's promise of killing all of Sub-Zero's friends and family before killing Sub-Zero himself.

Female ninjas
Mortal Kombat II had marked the debut of the female counterparts of male ninjas. Unlike their opposite sex, their basic designs change drastically throughout each game. They were first depicted with a leotard, a plain mask, head band and tight skin boots. By Ultimate Mortal Kombat 3, the design changes to a more detailed leotard split in the middle held together by thick threads, a mask, detailed boots and hair tied up in a small bun. As far as abilities go, they are just as lethal in combat as male ninjas, prominently employing the use of weapons in favor of hand-to-hand combat. Their slime, lithe build, combined with their agility and speed makes them much more difficult to handle in kombat.


 * Kitana - The 10,000 year old princess of Edenia. Kitana was adopted by Shao Kahn as his stepdaughter after the invasion of her homeworld and the death of her parents, King Jarrod and Queen Sindel. She eventually rebels against the tyrannical emperor and joins Earth's forces in defeating the Outworld menace, falling in love with the Earth champion, Liu Kang after the war. Having rescued the resurrected, but brainwashed Sindel from Shao Kahn's control, Kitana rules her liberated realm alongside her mother until the Deadly Alliance where she is killed, revived under Onaga's control and then set free by Liu Kang and Ermac. Wears royal-blue colored shades, fitting in with her status. She possesses several mystical powers such as flying and teleporting and wields a pair of steel fans in kombat.


 * Mileena - The half-Edenian, half-Tarkatan clone of Kitana, created by Shang Tsung to serve Shao Kahn as well as Kitana's 'stepsister'. As time grew by, her ambitions and resentment towards her original counterpart's status and beauty caused her to take up arms against Edenia. Wears a hot pink uniform. Unlike Kitana, Mileena's attire is much more revealing and decidedly Arabian in style, compensating for the hideous visage she hides with her veil. She possesses a couple of bizarre abilities and a pair of sai during kombat


 * Jade - Kitana's loyal bodyguard and closest friend. Jade survived the invasion of their homeworld but stayed in secret. She was later enlisted into Shao Kahn's army to track down Kitana, dead or alive. Choosing her friendship and loyalty over the emperor, she rebels against Kahn alongside her old friend, taking back Edenia. After the Deadly Alliance's triumph over Earth's forces, Jade and Sindel try to locate their fallen brethren, whom had already fallen under Onaga's spell. Wears shades of her namesake, retaining a variation of the traditional UMK3 ninja uniform. She possesses the ability to reject projectiles, among other abilities and wields a steel bo and 'razorrangs' in kombat.


 * Khameleon - Another mysterious survivor of the Saurian race and searching for Reptile, the only other known survivor of their extinct race. Khameleon almost succeeded but failed when Earthrealm's force triumphed, which had forced Reptile to run into hiding. She later resurfaces during Armageddon in order to exact her revenge towards Shao Kahn, indirectly siding with Earthrealm's forces. Khameleon, like Jade, retains a variation of the UMK3 ninja outfit, but wears shades of gray like Smoke and transparent skin. She possesses the powers of her female ninja counterparts, including their weapons.
 * Frost - Protege to Sub-Zero, won a competition to join the ranks of the Lin Kuei and took on in this position to steal the amulet that heralded leadership of the Clan. Has powers similar to both of the Sub-Zero brothers, to a lesser extent. Often manifests in the ability to freeze the ground near herself or her enemies.
 * Tanya - Edenian traitor. Initially allowed Shinnok's entry into Edenia. Has since earned the ire of Jade. Has stealth-based moves, such as the ability to turn invisibility.
 * Ruby - Warrior in Ermac's squad (Non-Canon). Sent by Shao Kahn to invade Earthrealm and sabotage their ability to enter Outworld. Eventually assisted Earthrealm's warriors in defeating Ermac's forces.