The unnamed Professor is a new character introduced in Metal Slug Attack and one of the prominent characters of that game.
A former scientist for the Rebel Army, he at some point joined the Martians after witnessing Rugname's power. He learned how to create clones, mutate beings and used his knowledge during his time with the Rebel Army to create various robots, such as his personal Ring Laser Mecha, the Mars Brain Robot, and Mars Gigantalos. He is fond of the Mars People, learning to communicate and create equipment to protect them from threats.
He is on poor terms with Navy while he was in the Rebel Army, serving as its scientific chief. During his time in the Rebel Army, he also had an assistant named Percier, who called him her "eternal servant", though he abandoned her when he defected to the Martians. He eventually took her back in during a raid to save Marty. Despite this, he thinks of her as somewhat boring and tends to ignore her.
After hearing that the Rebel Army got support from the future Rebel Army, he decided to ambush them. He surprised the Future Rebels and killed all of the infantry. The remaining rebels sent the Kraken after him, and after a decisive battle, destroys it. He takes the remains of the Kraken with him to study the technology of the future.
The Professor later appears again in the Extra Ops "Signal Red", where he is seen inside the Rugname trying to extract a special Brain Robot, accompanied by a red Ring Laser Mecha. Morden sends Vita to stop him. When Vita arrives, she battles the Mars Brain Robot and destroys it. The Professor then tries to kill Vita, but she dodges his attack and knocks him unconscious. He is saved when the red Ring Laser Mecha arrives, as Vita leaves after a brief confrontation.
Sometime after those events, in "Mad Scientists", the Professor builds himself a new Mars Mecha and attempts to learn more about Vita with the help of two Martians; Marty and Percier. He confronts Navy, though he is easily defeated by her. Before Navy can do anything, the two Martians appear to distract her and teleport away with him in tow.
In order to combat Vita, the Professor made a clone of Abigail (named Clone Abby), making it the same as her, though he made it emotionless to ensure absolute loyalty and completing tasks without question. He sent Clone Abby out on a test run, attacking a Rebel engineering facility where the new Emain Macha twins were being constructed. It severely damaged the Drache Macha which he was pleased with and told Abigail that he would improve on Clone Abby with the results it collected before having it depart.
He later created Clone Betty with the information from Clone Abby and sent it out on a test run. He also equipped three Martians with new equipment, stating that he wouldn't be around to protect them all the time and that they needed to do it themselves. When Clone Betty is hacked by White Baby, the Professor immediately recalls the group back and puts Clone Betty into its failsafe mode before removing the malicious program from it.
The Professor contacts the Regular Army to inform them of a brainwashing treasure that is causing everyone to go on a rampage. The Regular Army eventually neutralize the signal and he is impressed with their actions, stating that he obtained a lot of information despite being a spectator.
When Ariadna returns from a "memory trip" in "Revival of Intention", the Professor states that she is no longer human and that all the feelings she had are gone.
While creating more equipment for the Martians, he realizes that he is running low and tasks his two "children" in obtaining the materials for him. When they return with the materials, he pats the two on their heads for their successful mission.
He later sends out Clone Betty on a mission to obtain information regarding Amadeus' experiments and the clone asks him to make a tiger impression, though he refuses to do so out of embarrassment. When Clone Betty returns, having been defeated by Alma, he reassures it and states that it managed to obtain an acceptable amount of information.
In "Encounter of Unknown" he gives Halle her first mission and her accompanying Mars People Pocket asks the Professor for assistance as it is concerned for her safety. The Professor agreed to its request as he sends the Rugname to obliterate a new version of the Cabrakan.
Sometime after this, he participates in a vicious battle against the Rebel Army, battling Beatriz. Their fight is interrupted by the Great Mother's arrival, and he retreats with the other Martians.
While in the Rebel Army, he was designing a new robot that he planned to use to assist in the war effort - however, he was unable to complete it, as he didn't have the resources to do so, and commented on the Rugname, believing that the Martians could help him if he could reach them. Fast forwarding sometime later, the Professor is finally able to create his robot; the Mars Gigantalos, even surprising Percier. The Professor decides to test the Mars Gigantalos on a Rebel supply line, accompanied by his "children". It is implied that he took some injuries during the battle, as Percier goes off to check on him after applying first aid onto White.
As he researches for the Martians, he is caught by surprise when Abigail confronts him at a Martian facility, believing that she had died in her battle against Clone Abby. Having no means to defend himself, she quickly disposes of him. Given his extensive knowledge of cloning, it is possible that he may still be alive.
The Professor captures Marco, Eri and Tarma in order to study their minds. He's impressed with Marco and Eri, but is disappointed with Tarma. He also captured several Regular Army soldiers for experimentation, and after being defeated, Marty arrives and informs him to enter the Rugname.
His reasons for joining the Martians are detailed in "Utopia", where he was amazed by their technology. He successfully joins the Martians after defeating the Sol Dae Rokker and having made a new friend, the Mars People Neo, who he begins to call "Marty".
When Marty is abducted by the Rebel Army, he goes out to search for him with two Cadres. During the mission, he finds Percier and has her tag along, not wanting to leave her by herself. Apart from that, the events almost mirrors the Extra Ops "Black Future".
In "Cross/You", the Professor had a discussion with Navy regarding Vita. The Professor felt that it was best to suppress Vita's memories, as he stated several flaws that it had by not adding a personality modifier. Navy refused to do so, believing life in a different meaning. The Professor told her that she had one month to do it, or he would do it himself. This never happened, as he defected to the Martians sometime later.
Like in "White Breath", he refits three Martians with new equipment and sends them out to test it, even sending Clone Abby and Betty to oversee them in "We are the Mars People Rangers".
During the second summer party, the Professor unleashes a large amount of "boreal matter" on a popular resort island, not caring that it is neutral territory as they are already everyone's enemy. Trevor attempts to intervene but is captured and sent to the Rugname X for further experimentation. Nova and Odette confront the Professor, where he notes that the matter doesn't affect Invaders either. He reveals that he unleashed the matter onto the island as there are many prominent fighters, and he wants their data. In the resulting battle, the Rugname X suffers critical damage and he leaves, satisfied with the results he obtained.
- The Professor's mech is a Ring Laser Mecha / Mini-UFO combination, using a Vanguard's arms.
- After winning or while using his special, the Professor laughs in a similar way to most Rebel Army units.
- The Professor himself appears to be a reference to Dr. Emmett Brown. The two share a similar appearance, and the logo for the Extra Ops event he first appeared in, "Black Future", bears more than a passing resemblance to those used for the "Back to the Future" movie series. This is further supported with his assistant Marty, who shares the exact name and role as in Back to the Future.
- His mecha's control panel matches that of a NeoGeo arcade cabinet.
- He is available for purchase at the United Shop in the 4th United Front event.