Smoke is a ninja assassin who was turned from a human into a cyborg in the Mortal Kombat fighting game series. He made his debut in Mortal Kombat II as an unplayable secret character in human form, and first became playable in Mortal Kombat 3 in a cyborg form. He appears in the franchise's reboot, now retaining his human form in canon for the first time in almost two decades. His Street Fighter rival is Guy.
Smoke would not have his own storyline until he was featured in Mortal Kombat 3, where he was once again a hidden character, but accessible to players with the use of a code. In this appearance, he would be a tortured, human soul trapped in the body of a cyborg. His most defining feature is the fact that he constantly seems to emit a smoke or vapor. This, combined with his power to teleport and turn invisible, once made him one of the Lin Kuei's top assassins.
Of all the three cyborg ninjas, Smoke appears to specialize in stealth and speed. His powers as a human were unknown for the most part, but in both forms, his body emits a constant smoky fume, probably to confuse his opponents on the whereabouts of his location. In MKII, he was depicted as moving at extremely high speeds. From Mortal Kombat: Deception onward, Smoke is seen using smoke-related attacks, such as causing his opponent to cough as well as teleporting. Due to Smoke's 'upgrades', his body appears to be made out of smoke, or at least his nanomachines emulate the sensation of smoke. Whatever the case, due to Noob Saibot's modifications made on his body, he has become a demon nonetheless. In Mortal Kombat: Armageddon, he is seen to be able to mind control other people by inserting his gaseous mist into others. In Mortal Kombat: Annihilation, Smoke is armed with rockets, similar to Sektor, and has the ability to transform himself into smoke in order to ambush his enemies.
In Mortal Kombat (2011), Smoke remains in his human form and his abilities are explored deeper. It is revealed in his ending that he is in fact an enenra, a demonic creature composed entirely of smoke and vapor. As such, he is able to not only actively utilize his namesake as an extensive weapon, but he is also able to morph his entire body into a cloud of vapor, allowing him to move swiftly around his opponent as well as escape from enemies or potential captors.