The Twelfth Doctor is capable of regenerating into a new physical appearance.
 In the series finale, "The Doctor Falls", the Doctor faces an army of Cybermen and struggles to convince Missy to side with him; she is influenced by her past incarnation (John Simm), also on board the ship
In the series 10 premiere "The Pilot" (2017), it was revealed that the Doctor has spent decades working as a professor in St Luke's University in Bristol, giving lectures on time and life, assisted by Nardole

