So we are coming up to the season finale, and the question that still is not answered is who or what is Clara Oswald?
Spoilers below
Unlike most Dr Who companions we know relatively little about her. Most companions at least have some form of backstory by this point. Yet we know almost nothing of the current Clara incarnation beyond the fact that she works as a nanny.
So far she has appeared three times without history, once buried in the body of a dalek imprisoned in the Asylum (which may be in the future or the past as Dalek's are capable of time travel), once in Victorian London and once in current day London.
I've been reading around a bit and there are a few theories that seem to crop up on fan pages.
1) She is a family member of the Doctor. There are two avenues for this, one is she is related to the Doctor's Granddaughter, aka his original companion. The alternative is that she is related to his daughter that was accidentally cloned from him in his 10th incarnation. Given the destruction of Gallifery seems to occur in his timeline after his granddaughter disappears and he believed his clone daughter to have been killed, he probably wouldn't be on the look out for either of them. It would also tie in with the rest of the mildly incestuous events that seem to pop up in recent series; after all he has already had his mother in law try to seduce him. Or worse, she could be his own daughter, and one of the "spoilers" River Song cannot reveal.
Against that though is
2) She is a figment of the Doctor's imagination, and he has been driven mad by the loss of his last companions and/or the effort of the great intelligence (of whom little is known). Maybe he is still trapped in the Asylum with her as a final revenge of the Daleks? This is given some support by the fact that she has little personality (as some of my friends who hate her point out) that is not simply an extension of the Doctor himself.
Any other ideas?