Fox Ears

The Zoologist rotates her costume stock with the moon, and the fox pieces show up on only two of the eight phases, third quarter and waning crescent. Nothing in the world drops them and no other NPC carries them, so if her shop is showing something else your only option is to wait for the sky to come back around. Check the phase before you make the walk to her house.

Fox Ears and the Fox Tail count as accessories rather than armor, so equipping them normally eats room you want for wings or a shield. Put both in the social accessory row instead and the look costs you nothing. Reforging is pointless on either one, since there is no stat hiding under the costume to improve.