When the X-Men were visiting the Savage Land, Colossus saved Nereel and another member of the Fall People tribe from a T-Rex that attacked them. Nereel became fond of Colossus, and had intercourse with him as part of a memorial ceremony for another tribe member who did not survive the dinosaur attack. It was later revealed that Nereel had conceived a child, which she named Peter.
Some time later Colossus met Nereel and their son, but never realized that Peter was his child.
Years later, when his great-uncle, Vladimir killed himself, Peter, as with the rest of Rasputin family members, felt his death.