>Korra raised Naga from a puppy, and she is, as far as I know, the only
>extant tamed member of her species.

This is so, canonically; in UF there have been several generations of Naga's descendents in Korra's care (or possibly she's been in theirs) - as we've seen, quite a pack of them have accumulated in the Spirit World. What's more, she's had to find homes for the rest of the puppies, so some of her relatives, friends back in Senna Village, and so forth have adopted them over the years. By 2410, the extended clan represents a fairly well-domesticated branch of the species, even if everybody else at the South Pole does think the kids in Senna are crazy. :)

--G.
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