Details: Should you go to Paniola Town, you will find Team Skull demanding the bottle cap that a Vulpix has in its mouth. After defeating Team Skull, the Vulpix will run off. If you head to Route 8, you will then find it in the Aether Foundation Trailer. It won't be responding or eating, so you will be enlisted to nurse it back to health by visiting it every day. After a few days, you will get it back to full health. Once it reaches this point, the Aether Foundation will bring it to Mt. Lanakila where you can interact with it.