Shaun

Shaun or Father is the son of the Sole Survivor and the leader of the Institute

Background
Shaun was less than a year old when the Great War took place. His parents fled with him to nearby Vault 111, surviving the bombing. Shaun and his parents were frozen in cryogenic suspension as part of the vault's experiment.

An organization known as the Institute developed after the war, and its scientists sought unmutated DNA for their synthetic human project. They discovered records of the vault and attempted to acquire the DNA from the cryogenically frozen inhabitants of the vault. Institute mercenary Conrad Kellogg kidnapped Shaun, murdered one of their parents, and left the other alive as the "backup," refreezing them before leaving with the baby. His DNA was successfully utilized by the project.

Shaun was subsequently raised by the organization and later in life, became their leader, known as "Father." Curious about his surviving parent, he releases the Sole Survivor from the cyropod to see what choices they would make. If one chooses to oppose the Institute, the Sole Survivor has the opportunity to meet with Shaun one last time when they infiltrate the location. Shaun, now elderly with terminal cancer, will express his disappointment in their child's decisions and viewpoints, stating that it is "delusional" to consider synths sentient. A series of Charisma checks result in Father delaying access codes to disable some of the hostile synths. Shaun had the young boy reprogrammed to believe that the player character is their parent, and records a message to the Sole Survivor that states, "I would ask only that you give him a chance. A chance to be a part of whatever future awaits the Commonwealth."

Appearances
Shaun appears in Fallout 4 and Fallout Shelter Online.