Nardole.

About Nardole

Nardole is a fictional character created by Steven Moffat and portrayed by Matt Lucas in the long-running British science fiction television series Doctor Who. He is a companion of the Twelfth Doctor, an incarnation of the alien time traveller known as The Doctor, played by Peter Capaldi. In-universe, Nardole is a humanoid extraterrestrial being who serves as an employee to the Doctor's wife, River Song. He is decapitated and forcibly integrated into an alien cyborg body, but has his body rebuilt by the Twelfth Doctor. He becomes a full-time companion following the episode "The Return of Doctor Mysterio", and subsequently appears in his role as a companion and supporting character throughout the show's tenth series and then makes a cameo in the 2017 Christmas special "Twice Upon a Time". Lucas briefly reprised the role in a short written in support of the Black Lives Matter movement.