The Doctor looks and seems human. The Doctor is good-looking, sexy and witty, and could be mistaken for just another person in the street. But the Doctor is a Time Lord: a 909 year old alien with 2 hearts, part of a gifted civilization who mastered time travel with the TARDIS. The Doctor saves planets for a living and is very, very good at it. The human race will survive - but only with the Doctor's help.