I fear that this question may be unanswerable, but I wonder if I missed a subtle clue in Doctor Who: do we know if Osgood is either the original human or the Zygon copy?

And why was the answer to this question so important to the Doctor? If I'm not mistaken, he asked (the surviving) Osgood three times which she was, insisting the answer was important.

The episodes in question are:

  • 1
    I'm just about to sit down to watch the second one, but in the first part, it was my impression that the doctor was correct (based on her reaction) in believing she was a human, even if the reasons he did so were wrong.
    – Shamshiel
    Nov 7, 2015 at 22:03
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    I also tend to think she's human, because the other Osgood, showing up at the end of Inversion, said she was a Zygon. And, well, there's one human and one Zygon, so... unless they're lying of course. </spoiler> But I'm not sure why it was important to the Doctor.
    – Mr Lister
    Nov 7, 2015 at 22:16
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    Also, if you think her first name is Petronella, you might as well think the Doctor's first name is Basil. Which brings up another question. Why did the other Clara say her name was Bonny? Why not Clara? </spoiler>
    – Mr Lister
    Nov 7, 2015 at 22:21
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    I'm not sure it matters much which she was. I think the bigger question is why the Doctor thought it was important. At first I thought it was because of the buttons in the Osgood box. "Truth" would change her into her Zygon form, "Consequences" would fixate her human form forever (if she was a Zygon that is). Of course that would depend on which Osgood box we're talking about. So, that would matter. But as it turned out, the buttons didn't do anything. Unless the doctor was lying. And if you're still reading this and you haven't seen the episode yet, that's your own fault isn't it. </spoiler>
    – Mr Lister
    Nov 7, 2015 at 22:29
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    Total guess (about why the Doctor thinks it’s important): Zygon!Osgood can preserve the body print, but she can’t access extended memories. So if human!Osgood knew something and the Doctor thinks she would have been unlikely to share it with her Zygon counterpart, that information is lost. And is probably going to be plot-critical quite soon.
    – alexwlchan
    Nov 8, 2015 at 9:46

7 Answers 7


Well, when we see the Doctor and Osgood on the beach in "the Zygon Inversion", you may have noticed that...

...Osgood's glasses were thrown off her face and broken - presumably from a heavy parachute landing. The Doctor fixes them for her with some duct tape.

So, following on from previous discussions about the about the extent and limitations of their shape-shifting abilities, this would indicate that the Osgood we've been following has removable non-Zygon glasses and is, therefore, human.

I would be surprised that the Doctor hasn't formulated a hypothesis on Zygon abilities and Sherlocked the truth of the matter which would imply that, whilst he might know the answer, the subtleties of the reaction to the question and the response itself may reveal more to the Doctor about the character of Osgood which ultimately leads to the question/offer that only the special and extraordinary hear.

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    Oh, that's good! Great deduction! Nov 8, 2015 at 12:22
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    It's possible that Zygood has begun to wear normal clothes, since she seems to spend most (if not all) her time in human form anyway.
    – George T
    Nov 10, 2015 at 8:08
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    Yes, I agree that is very possible @GeorgeT but it is not in keeping with observed behaviour. The poor Zygon who was made a target for reversion, for example, had enjoyed his form and his life for a long time and yet his clothing was Zygon.
    – Kerr Avon
    Nov 10, 2015 at 14:47

At the very end of the inversion episode both Osgood's use their inhalers in different ways. The "new" Osgood sticks her thumb under the inhaler whereas the "old" osgood holds her thumb on the side.

Looking back at the first episode where Osgood is zygonised 😝, the zygon version holds the inhaler the same as the "old" Osgood does in the invasion/inversion episodes. Which to me means that original Osgood is no more 😒

  • Interesting theory, though I would have thought the Zygon would copy habits as well as appearance, since they have access to the originals memories? If you could add screenshots as evidence you would have a quality answer. (PS: welcome, please check out our tour.) Nov 8, 2015 at 19:19
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    @Wikis, during one of the commercial breaks, there was a clip of an interview with Ingrid Oliver where she said she put in effort to make sure there were subtle and consistent differences between the human and Zygon versions of Osgood.
    – Brian S
    Nov 9, 2015 at 8:07
  • @BrianS: which channel? Not BBC if their were adverts. Do you have a clip you can post? Nov 9, 2015 at 8:10
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    @Wikis, It was the BBC-America airing that I was watching. This clip contains some of the same interview, but it's not exactly the same as what BBCA put up during the break: youtube.com/watch?v=vk5AAwXgrXU
    – Brian S
    Nov 9, 2015 at 8:15

Alright, here is my theory (spoilers are coming, so mind your step!):

Osgood is... HUMAN!

From what we have seen of this species, Zygons require to keep originals alive to be able to shift into their shapes. Not only that, they must keep them alive at least long enough after cloning them so as to learn to immitate habits, interrogate them and access their memories.

If Zygella – or Bonnie, hahah! – was able to take the form of Osgood, that means there IS an original out there, alive, to make a copy from. HUMAN, ORIGINAL and ALIVE :D!

BUT... this theory only works if the afore mentioned MO is the ONLY way for Zygons to make copies.

The counter-theory includes an alternative where Zygons ARE able to copy another Zygon already in the shape of someone (or something) else, not only being able to preserve body prints after the originals are gone (or killed) but also able to reproduce such body prints (making several copies without the originals).

As for why the Doctor finds the question important, I agree with Kerr Avon:

"[...]the subtleties of the reaction to the question and the response itself may reveal more to the Doctor about the character of Osgood which ultimately leads to the question/offer that only the special and extraordinary hear."

The Doctor may have been testing her, somehow? So to speak.

All in all, and for as much as I do crave to know... the truth is we SHOULD NOT CARE. It's been said before and I agree. "The Osgoods" are the whole point. There being two of them, living like hybrids (sort of) and not letting anyone know which one belongs to which species, makes them THE ULTIMATE peace treaty. The ultimate BREATHING peace treaty. In a box. Of flesh. A twin box... I have to stop.

PS1. I'd like to take a moment to acknowledge the love these two sisters developed for one another –

and the hurt of the surviving Osgood resulting from the other's death.

= = = = =


To tip the scales a tad further, there is also the fact that the Zygon cloning process involves body prints taken TELEPATHICALLY. Which leaves the doors open for the possibility of Zygons being perfectly capable of sharing information and copying body prints off another Zygon.

Additionally I have read a third alternative theory on Facebook,

of there being THREE Zygons from the beginning, keeping an original human Osgood in a pod with two Zygons roaming the streets in Osgood form and all three telepathically linked, sharing information regardless of location... clever!

I have to admit it IS far fetched but most interesting!

PS2. In any case, for as much as I do want her to be the human, original Osgood – because we loved her and there is loss in her death even if there are copies of her left to spare, plus poor Kate... ah the feels T_T – as others have already stated before, it makes for a stronger, way more powerful statement for her to be the Zygon Osgood. So devoted, committed to peace, and so hurt by her human sister's death. I've used the terms before: THE ULTIMATE BREATHING and walking peace treaty.


In part one Osgood is running away from the Zygons and hides under a table. You can tell that it was the human Osgood because she had to use her inhaler.

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    Welcome, please check out our tour. I don't think that is evidence because (minor spoilers) at the end of part 2 there are two Osgoods of which one is definitely a Zygon. Both use inhalers. Nov 8, 2015 at 6:08
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    They also both used inhalers during Day of the Doctor before one of them was no more
    – BBlake
    Nov 8, 2015 at 6:27

Here's my theory. When Human Osgood was cloned by the Zygon it was wearing the 4th Doctor's scarf. Now the human Osgood is an obsessed fan with the Doctor like all of us. The human Osgood has so many tokens of the doctor. Those are our clues as to which is human. The human Osgood changed from the 4th Doctor's scarf to his famous question marks. The safe is behind the original portrait of William Hartnell, Doctor #1. At the end of this new episode The Zygon Invasion, the new Osgood is definitely Zygon with the 4th Doctor's scarf. Twice showing a Zygon with the scarf.

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    But both the Osgoods (the one killed in Death in Heaven, and the one seen in The Zygon Invasion) are fans of the Doctor. They've both taken to wearing Doctor-themed clothes the original Osgood in Day of the Doctor didn't wear (bowtie and question marks respectively).
    – Rand al'Thor
    Nov 8, 2015 at 19:13

Could the Doctor be planning to use zygon copying technique to help clara and thats why he kept asking if osgood was human or zygon? All season, he just wants clara safe and testing boundaries of changing history. Maybe, he wanted to know how close the zygonn copy is to human counterpart, go back in time, make sure danny is copied, now he is safe in pod, find him, and the Pinks can get started on time traveler astronaut Orson. Jenna said "no new love interest" for clara. Well, what about old love interest? Besides how can Orson happen without danny?


I'm seriously wondering if Osgood could be a future incarnation of the Doctor. Look at her fascination with the Doctor's outfits. Yes, this could be a fangirl kind of thing, but it would also explain why Capaldi's Doctor is fixated on whether or not she is the human version or not. We've seen something similar before. In Planet of the Spiders, Cho Je is the future incarnation of the abbot. Of course, we also see the Doctor's future incarnation in Logopolis as well - though not exactly solid. Just a weird theory here.

  • Do you have any hard evidence besides a fascination with the outfits? If so you should edit that in.
    – TheLethalCarrot
    Aug 18, 2020 at 6:42

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