The Doctor is back, and he's a lot younger than his predecessors.

26-year-old British actor Matt Smith is the eleventh person to take on the intergalactic Time Lord role on 'Doctor Who'; he joins a long line of acclaimed thespians, including David Tennant (who just hung up his Doctor trenchcoat last year), Chris Eccleston, and the legendary Tom Baker, who played Doctor from 1974 to 1981. While Smith looks strangely like a hybrid of Eccleston and Tennant, he brings a youthful energy all his own to the sci-fi show.