Pegg was an orphan who was taken in by a kind scientist named Professor J. Olson. Pegg lost his arm in an explosion caused by a power reactor when he was young, that also took his house, and his father and brother. He and his mother were left with no money and little possessions and his mother became unable to care for him. She left him on the top step of Olson's lab in hopes that the professor would give him a kind and welcoming home. The professor adored Pegg from the first moment he laid eyes on him. He became determined to raise Pegg as his own son. Pegg loved Olson and his new home, but there was always one thing in his life that brought him down. He longed to have two arms like other children in the city, and felt insanely jealous every time he saw them playing together. Olson noticed this, and he began to feel incredibly sorry for the child. The professor set to work to create a mechanical arm for Pegg, who was overjoyed when he finally received it.
Over the years, Pegg took more of an interest in Olson's work. The professor was more than happy for Pegg to become his apprentice.