Alfie Owens
Alfie Owens was the son of Craig Owens and Sophie.
Biography
According to the Doctor, who claims to be able to speak baby, Alfie preferred to call himself "Stormageddon, Dark Lord of All". He called Sophie "Mum", Craig "Not Mum", the Eleventh Doctor "also Not Mum" and everyone else "Peasants".
In 2011, while his mother was away for the weekend, Alfie met the Doctor, who could speak to him. Alfie accompanied them to investigate a Cyberman invasion and was transmatted onto a Cyber Ship. That night, while his father was on a milk run, the Doctor babysat and saved Alfie from a Cybermat attack. The next day, Craig left Alfie with Val, a store clerk, while he went to help the Doctor fight the Cybermen. When he boarded the Cyber Ship, however, the Cybermen tried to convert him into a Cyber-Controller. Alfie began to cry during his conversion. Hearing his baby cry not only re-awakened Craig's emotions and freed him from the Cyber-converter, but caused all of the Cybermen to start feeling again. The emotional feedback made the Cybermen and their ship explode.
Alfie's crying saved Craig, the Doctor and Earth and the Cybermen were defeated. After this, the Doctor claimed that Alfie began calling Craig "Dad" and now preferred the name Alfie to "Stormageddon".
Alfie's first word was "Doctor". (TV: Closing Time)
Behind the scenes
In the TV episode Nightmare in Silver there is a character named Ha-Ha who says that he's heard stories of the Cybermen since he was in his cradle. Some fans believe that this hints that Ha-Ha may be a grown-up Alfie.