Steven Moffat's 10 Greatest Additions To Doctor Who

Introduced as a UNIT employee and fan of The Doctor in 'Day Of The Doctor', Whovians quickly took Osgood into their hearts, seeing her almost as one of their own. From her humble beginnings as a supporting character in the 50th anniversary special, Osgood soon became the central figure of her own gripping storyline.

Seemingly murdered by Missy in 'Death In Heaven', 'The Zygon Invasion/ Inversion' two-parter revealed that there had been two Osgoods, the human and her Zygon double, and that the pair had been charged with keeping the peace between the two races. The surviving Osgood refuses to tell The Doctor which one of them had been killed, insisting that it did not matter. The Doctor eventually agrees.

Osgood was an audience surrogate who became much more, a hero in her own right, easily one of the most popular of The Doctor's 'almost companions'.