Nagini: If she's not a Horcrux, what the heck is she?

[Lisa]

No: HPFGUIDX 171953

--- In HPforGrownups at yahoogroups.com, "mandorino222"  I have no canon 
in front of me, but has everyone already rejected the 
> idea that Nagini is the snake that Harry freed in SS?  Do their 
> descriptions conflict with ne another? 
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Lisa:

Nagini is a python; the snake Harry freed was a boa constrictor.