With the semi-recent change which turned bear teeth and boar tusks into curiosities, all lootable animals now have available curiosities to them apart from the fox (as far as I know). While foxes undoubtably will be more popular to hunt in w5 thanks to the new importance of INT, I still feel it's inconsistant that this animal doesn't have a curiosity linked to it.
What I suggest is that when a fox is skinned, the player gets a 'fox tail' curiosity. In addition to being the regular curiosity thing that we use because we're all such curious little buggers, it could also be added as a component to the fox hat. Hey, the sprite does have a fox tail after all!
But yea, that's about it. Equal rights for foxes!