Plume Fossil is an item in the “Dex completion” category (Items). It costs ₽7000.
In-game descriptions
| Black / White · Black 2 / White 2 | A fossil of an ancient Pokémon that flew in the sky in ancient times. It appears to be part of its wing. |
|---|---|
| X / Y · Sun / Moon · Ultra Sun / Ultra Moon · Let’s Go, Pikachu! / Let’s Go, Eevee! · Sword / Shield | A fossil from a prehistoric Pokémon that once lived in the sky. It looks as if it could come from part of its wing. |
Where to find it
Not placed on the atlas maps (so far: Red/Blue and Generation 3).
Sources : PokeAPI (items, item_flavor_text, machines) · atlas · pokeemerald species_info.h