What is Nagini?

[justcarol67]

No: HPFGUIDX 157114

I still think that Nagini is a Horcrux, but suppose that she isn't. Is
she just some unusually large snake that Voldemort the Parselmouth
developed a close relationship with? Why didn't she die like the other
snakes when he possessed her, and why does she stay around him like a
pet? Could she be a familiar spirit? I don't mean in the Old Testament
sense: "A man also or woman that hath a familiar spirit, or that is a
wizard, shall surely be put to death" or any literal connection with
Satan since that's not the mythos of the HP books but a spirit or
demon in animal form that serves a wizard. She's clearly magical and
her venom has magical properties that somehow sustain Baby!mort--in
fact, help create him (along with the equally magical unicorn blood).

I also think that one of the challenges facing Harry in Book 7 will be
fighting Nagini (foreshadowed by the battle with the Basilisk in CoS)
and that she'll be more wily than the Basilisk, actually talking to
Harry as the "worms" (dragons) taunt their intended victims in
Tolkien's works. But what would be his reason for killing her if she's
not a Horcrux? What if he kills her thinking she's a Horcrux and
there's really another Horcrux left that he doesn't know about?

Carol, imagining Harry destroying Nagini with the Sword of Gryffindor
and really hoping that she's a Horcrux because it would greatly
simplify matters for Harry, the reader and JKR