History: Mikhail Ursus was one of the first known mutants born in the Soviet Union in the 20th Century to survive past childhood. Up until the time of his birth, the Soviet government had performed euthanasia on all mutants at the first manifestation of their superhuman powers. Due to the efforts of scientist Piotr Phobos, the government was made to see the potential value of superhumans serving the state and Phobos soon opened a private school to train mutants. Mikhail Ursus was among the first of the many mutants trained by Phobos. Unknown to both his students and the Soviet government, Phobos had built a device to siphon off energy from his students to give himself artificial powers of his own. The process tended to kill the subjects after a time, and Phobos explained their deaths as training casualties. When the second Red Guardian discovered Phobos's activities. Phobos managed to overpower her and went into hiding, giving two of his students totems through which he could still siphon their power.

Following certain field work, the three best-trained students of Phobos's school were reunited and organized by the government into the elite Soviet Super-Soldiers. Ursus was given the code name Ursa Major. The first mission of the Soviet Super-Soldiers was to investigate the contained radioactive area of Khystym known as the Forbidden Zone. There they discovered that their former teacher was engaged in a project to radioactively contaminate all of the Soviet Union in order to foster the birth of more mutants whose powers he could eventually siphon. The Soviet Super-Soldiers, aided by the Hulk, thwarted Phobos's plan and brought him before the government to stand trial.

Although the Super-Soldiers resolved to remain together as a team, they vowed to never again unquestioningly serve the state. They have subsequently undertaken one government mission, but generally act independently. They were based in a scientific fortress in the region of Khystym.

Later, Ursa Major followed Vanguard into the employ of General Tskarov, a communist sympathisizer who wanted to undermine American business along the east coast. They only agreed, however, in order to find the missing Darkstar, whom Ursa Major found in Tskarov's labs, being experimented on. Ursa, Darkstar, and Vanguard then joined the Black Widow and Daredevil in taking Tskarov down. Presumably, Ursa returned to the mother country to continue his fight there.

Height: 6 ft. 3 in., (transformed) 7 ft. 5 in.
Weight: 255 lbs., (transformed) 955 lbs
Eyes: Brown
Hair: Brown

Strength Level: In his untransformed state, Mikhail Ursus possesses the normal human strength of a man of his age, height, and build who engages in intensive regular exercise. Transformed into his bear form, he can lift (press) approximately 1 ton under optimal conditions.

Known Superhuman Powers: Ursa Major possesses the power to physically transform himself into a brown bear: The transformation, which can be triggered at will, takes about 10 seconds. When in bear form, Ursa Major possesses superhuman strength greater than that of an equivalently sized bear. He has the reflexes, stamina, and resistance to injury of an adult Siberian bear. Ursa Major retains his human intelligence and ability to speak while in animal form. There does not appear to be a limit as to how long he can remain in his bear form. Where the added 700 pounds of muscle tissue, flesh, bone, and hair come from when he alters his form is not yet known.