Hey, Jimmy. I've got no idea what they're from. I've been trying to figure it out. They're some kind of tail or flight feather, I think. They're too solid to be downy or semiplume feathers.

... But I've never seen a Pokemon with this kind of feather, and the way it's curved is... weird. If we were on Earth I'd say that nothing could really fly very well with how curved it is... but I don't know. There's also no way a single Pokemon could lose that many feathers and still be flying around.