The Professor is a new character introduced in Metal Slug Attack.
A former scientist for the Rebel Army, he at some point joined the Martians after taking an interest in their technology. Joining the Martians, he learned how to create clones, mutate beings and used his knowledge during his time with the Rebels to create robots based from the aliens' designs, such as his modified Ring Laser Mecha and the Mars Brain Robot. He also learned how to communicate with the Mars People.
He seems to be impressed with Marco Rossi due to his ability to create "life" (Marco created MS-Alice, an AI). He is also interested in Eri Kasamoto, as while examining her memories, he was impressed with the military experiences she had and planned to use it for future purposes.
With the release of Navy, another Rebel scientist, it is implied with her infobox that she did not get along with him while he was the 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.
After heard that the Rebel Army got more support from Future Rebels, he got interested in their new technology. He surprised the Future Rebels and killed all of the infantry. The remaining rebels sent the Kraken after him, and after a decisive battle, defeats 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 a disguised Martian. 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. It is presumed that he was aware of her crush on Trevor and not aware of the stronger Nova. 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.
More of the Professor's backstory is revealed during Another Story. He first encounters P.F when they try to get close to the Rugname to free captured prisoners. While the P.F squad is unconscious, he examines their memories and is impressed with Marco creating life from inorganic sources. He is also impressed with Eri's memories and expresses displeasure with Tarma, stating that he is simple minded. After the battle with the Rugname, he leaves with his Martian friend.
While being part of the Rebel Army, they are under attack by the Martians. The Professor is amazed with Martian technology and wishes to join them. Abigail tries to escort him to safety, but is stopped when she sees Donald Morden being abducted by a Dai-Manji. He tries to get an audience with Rootmars, but is unable to as the Martians prevent him from doing so. A common Martian approaches him and says that Rootmars will allow him to join if he can prove his strength. With the Sun Stone of the Sol Dae Rokker still on Earth, he decides to go there and claim it first and leaves quickly.
He later encounters the Martian again and asks why he came despite being weaker than him. He collects samples from Rebel Army soldiers brainwashed by the Sol Dae Rokker, amazed by the level of brainwashing it is capable of. The Martian protects him from an LV Armor and dies, which has some impact on him. After repelling the latest attack, the Mars People Elite come to carry their comrade away. The Professor argues that he hasn't finished his test yet, so the Mars People Elite decide to accompany him. While battling the Sol Dae Rokker, the common Martian mutates into a Neo Martian and helps him defeat the Sol Dae Rokker. Passing the test, the Mars People Elite allow him to join.
When Marty is kidnapped by the Rebel Army, the Professor leads a rescue effort to find him, with the help of his assistant Percier. They find Marty, who is badly drained of his energy as the Rebels discovered that the stronger the Martian, the more future energy they have to open the "Big Gate". Morden confronts the Professor and taunts him for defecting to the Martians, claiming that they will not be able to stop the Kraken. The Professor and his comrades destroy the Kraken and leave, telling Morden that he won't forgive him for harming Marty.
The Professor later makes a flashback appearance in "Cross/You", where he argues with Navy over Vita about adding a personality modifier and to let her memory find peace. Navy refuses and he gives her an ultimatum of one month before he would forcibly apply it to her if the change was not made. However, he did not do so, as sometime between that argument and the deadline, he defected to the Martians.
- 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.
- When placed in the same Metal Slug Attack deck, he and El Dorado form the "New Face II" team. This lowers their AP cost for sorties by 10%.
- 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.