By his own account, the Stranger is a composite being possessing the combined strength and intellect of the billions of humanoid beings who once lived on the planet Gigantus, an ancient world in the Andromeda Galaxy whose size approached the limit at which a planet can exist before fissioning into a sun. Gigantus, the home of a highly advanced and pacifistic people, was the target of the imperialistic race of Eternians, who decided to destroy Gigantus when it proved too big to conquer. Before their world’s destruction, however, a vast fleet of Gigantian escaped to retaliate against their attackers. After destroying Eternus, the Gigantians in some as yet unknown way melded their minds into a single being, apparently to one day combat Eternians’ similar composite entity, the Overmind. It is not yet known what the process of this merger entailed: whether the composite-form’s body is an artificial organic construct or one of the Gigantians’ bodies enhanced to be a suitable receptacle for his race’s mental and physical might. This being, later to become known as the Stranger, has existed for some eons now, engaged in the same pursuit of knowledge that had engaged his race.
The Stranger happened upon Earth in the mid-20th Century, apparently attracted by the sudden proliferation of superhumanly powered beings on Earth. Investigating some of these beings the Stranger encountered Magneto and his Brotherhood of Evil Mutants, and the original X-Men. The Stranger took Magneto and the Toad with him to his home-base to study. Apparently from his observations of Magneto and the Toad, the Stranger concluded that the powers in the process of development by the denizens of Earth would be misused and, in time, become a threat to other worlds. Thus he journeyed to Earth in two occasions for the express purpose of limiting Earth’s population through a random purge. On each of these occasions, he was convinced by the selfless actions of Earth beings (the Hulk and scientist Al Harper) the Earth had the potential for good. After his second attempt to destroy Earth, the Stranger declared it safe from any future reprisals.
Since that time, the Stranger has employed his vast powers on behalf of the Earth. The first of these incidents pitted him against his ancient enemy, the Overmind. The Stranger used his superior power to imprison the Overmind on a mole of dust. The second time he assisted Earth in the deactivation of the Null-Life Bomb, the same device that he once invented to destroy Earth’s population. The third time he came to Earth was to thwart a plot by the Olympian god Pluto.
The Stranger remains an enigmatic being, studying the phenomena of the universe for unknown reasons, and acting toward other living beings with unfathomable motives.