Doctor Mikhail Sergeyevich Cossack

"Besides, I know of these robots. They're some of the finest ever built, and their creator would never intend for them to cause any harm."

- Dr. Cossack

Dr. Mikhail Sergeyevich Cossack (Ｄｒ．ミハイル・セルゲイビッチ・コサック) is the central antagonist in Mega Man 4. He is a Russian robotics engineer affiliated with the Stravinsky Science Academy, and lives with his daughter, Kalinka Cossack. His hobby is watching ballet.

Mega Man 4
In Dr. Cossack's debut, he sent a letter to Dr. Light stating that he has created eight Robot Masters (consisting of Bright Man, Dive Man, Dust Man, Drill Man, Pharaoh Man, Ring Man, Skull Man, and Toad Man) and sent them to take over the world, in order to show the world his genius. Mega Man set out to defeat the eight new Robot Masters, and made his way to Dr. Cossack's Citadel. Just as he was about to defeat Dr. Cossack in the Cossack Catcher, Proto Man appeared with Kalinka and revealed the truth: Dr. Wily had kidnapped Kalinka and forced Dr. Cossack to work for him as ransom.

Mega Man 5
After Dr. Wily's defeat in the previous game, Dr. Cossack built a robotic bird called Beat for Mega Man to assist him in protecting the world. Dr. Cossack does not appear in the game, only being mentioned in the manual as informing Mega Man of Light's capture, and increasing the firepower of his Mega Buster's charge shot. In the Rockman Complete Works version of Mega Man 5 and its port in Mega Man Anniversary Collection, Cossack serves as the main guide in Navi Mode.

Wily & Right's RockBoard: That's Paradise
Dr. Cossack is one of the playable characters. His objective is to build a new lab to continue his experiments.

Rockman ×over
Dr. Cossack, along with Dr. Light, is responsible for the creation of the Reploid OVER-1, the main protagonist of the game. He appears in Battle Memory.

Mega Man (Archie Comics)
Dr. Cossack first appears in Archie Comics' Mega Man comic series in the fourth graphic novel, Spiritus Ex Machina. According to this continuity, he had travelled to America as a college student while undergoing his thesis in robotics research, and was likewise an old friend and colleague of both Dr. Thomas Light and Dr. Noele Lalinde because of this.

Mega Man Megamix
Dr. Cossack is a robotics engineer from Russia. After graduating with a degree in robotics from the Ural Institute of Technology, he got a job at the Stravinsky Science Academy. One day, Dr. Wily kidnapped his daughter, Kalinka Cossack, and in exchange for her safe return, he was forced to lead eight robots he created into battle against Mega Man. After the truth of this incident was revealed, Dr. Light helped Dr. Cossack clear his name and return to the good geaces of the scientific society. Since then, Dr. Cossack has intensified his efforts in the research and development of robots. He became good friends with Dr. Light and his robots, and created Beat as gift for Mega Man. He is the proud recipient of the Brzezinski Science Award and the Scientific Achievement Award, as well as numerous other prestigious awards.

In Grim Reaper of Resurrection, Dr. Cossack is kidnapped by Skull Man during a live interview with Charlie about a book he wrote, The Future of Human-Robot Relations, selling over ten million copies worldwide. Mega Man and Dr. Cossack's robots rescue him.

After the events based on Mega Man 6 in "The Greatest Enemy in History", Dr. Cossack went to Japan with Kalinka, Dive Man, and Drill Man to help Dr. Light. They first checked the ruins of New Metropolis, where they found the real Mega Man and repaired him, and also Yamato Man and the other robots that were under Mr. X's control.

Dr. Cossack also appeared in Mega Man Gigamix, where he created Duo with the large arm of the white alien robot and assists in the battle against the Stardroids.

Rockman 4
Like the game, Dr. Cossack tries to conquer the world, but this is due to Dr. Wily capturing his daughter, Kalinka.

Rockman 5
Dr. Cossack gives Beat as a gift to Mega Man, and assists him in his search for Dr. Light and Proto Man.

Rockman 6
Dr. Cossack has a brief appearance in the first chapter, where he talks with Dr. Light about the robot tournament.

Rockman 8
Dr. Wily kidnapped Kalinka again to force Dr. Cossack help him with the Evil Energy. After Duo damages Wily's stolen flying laboratory, Wily escapes and Cossack goes after his daughter. The two are rescued by Roll, Beat and Auto while Mega Man and Rush fight against Tengu Man.

Rockman: Yomigaeru Blues
When Dr. Cossack hears of Dr. Light's partnership with Dr. Wily, he goes to Dr. Light's Laboratory and finds Roll, Eddie, and Beat dismantled. He repairs them and goes after Mega Man with four of his robots to help him. When he arrives, Proto Man was damaged and he repairs him while Mega Man and the other robots go after Dr. Wily and the Wily Patrol.

Mega Man Through the Ages
Dr. Cossack, alongside his daughter Kalinka, were shown waiting for Mega Man close to the 1991 banner, with a 30th Icon containing the key art and footage for Mega Man 4, being at their feet.

Trivia

 * At one point in development, Dr. Cossack was actually named Dr. Vice (Dr.ヴァイス).


 * Cossack's name, while sharing the name of the military communities of Ukraine and South Russia, may be based off the dance known as the 'Cossack,' alternatively known as a 'Hopak' or 'Gopak'.


 * Dr. Cossack's full name may be based on the last Soviet leader, Mikhail Sergeyevich Gorbachev.


 * In the same fashion as fellow scientists Albert Wily and Thomas Light, Master Mikhail of the Sage Trinity in Mega Man ZX Advent was named after Dr. Mikhail Cossack.


 * Despite being mentioned in Beat's data in Mega Man & Bass, Dr. Cossack, himself, is absent in the game's database.


 * The Mega Man animated series version of Dr. Cain bears a slight resemblance to Dr. Cossack.
 * Dr. Cossack is briefly mentioned in Mega Man 11's Galary Database as being the creator of Tundra Man.