Celebrim
Legend
Essentially, our group is throwing around the idea of an elephant with a few levels in druid.
In my game, communities of animals are led by spirit beings that looks after their interests. Actually, all animals are spirits of a very minor sort, but collections of them produce expectional beings. It's for this reason that hunters must be very careful to apologize to animals that they slay and to explain the need that they had in hunting them. Otherwise, the animal spirits will become hostile, and in addition to this ensuring future poor hunting, they can be quite powerful and wreck a terrible vengeance.
It wouldn't at all be unusual in my game for the matriarch of a herd of elephants to have 2-4 PC levels. The chief of the elephants world wide is among other things a 16th level character.
we're not even completely sure if it'll play a part in one of our campaigns, if it'll be a pc, npc, monster, or who will dm.
But either way it's become a topic of conversation, with a lot of "does that even work?" In the mix.
Again, what works is whatever the DM wants to work. I want a world where it makes sense for lumberjacks to apologize to trees they cut down and to make offerings to the forest, and where hunters have a legitimate reason for performing rituals after slaying a deer. So I make what I want in the setting work. This isn't a violation of the rules. Even without invoking Rule Zero, you could formally create a template like 'Wise Animal', with the extraodinary abilitiy: "This animal can gain class levels as an exception to the normal rules for animals." That would be fully within a DM rights and expected purview.