A quiet, polite, lonely immortal esper about which little is known, he is called "Locke the Superman", but often denies being so. It is not known where or when he was born, and if asked, Locke will say he does not remember. It is entirely possible this is true. However, when asked by Cornelia Prim in "Millennium of the Witch" which star he was from, Locke replied "Toa."

He has appeared at various times throughout the history of the galaxy, either as a direct influence, an indirect influence, or a simple observer. Using his esper abilities, Locke can learn and do most things more quickly than a normal human. His power also allows him to remain eternally young, or even turn himself into a child again to be adopted by kind-hearted families. It is speculated he remains youthful as an excuse not to take responsibility for whatever cause he is approached for, since no one expects youths to have such responsibilities.