Daniel Anthony
From Tardis Wiki, the free Doctor Who reference
Daniel Anthony (born 4 October 1987) played Clyde Langer in The Sarah Jane Adventures. At the end of that series, he was a twenty-three-year-old playing a seventeen-year-old. In TV: Death of the Doctor, he briefly played the Eleventh Doctor, whilst the Doctor was using Clyde's body to comunicate with Sarah Jane Smith, though Matt Smith's voice was dubbed over his.
Anthony also played Delong in AUDIO: Wirrn Dawn. This role gave him unique status. He was the first BBC Wales series regular to have participated in a Big Finish production only after their DWU debut.