The Doctor is a Time Lord: a 900 year old alien with 2 hearts, part of a gifted civilization who mastered time travel. The Doctor saves planets for a living—more of a hobby actually, and the Doctor's very, very good … David Tennant, Matt Smith, Peter Capaldi, Jenna Coleman, Billie Piper, Karen Gillan, Nicholas Briggs Added on HBO 2023-06-27. Youtube Trailer