Community sources disagree on Feathers’ rarity (Common vs Uncommon). No official source found as of v1.0.64—treated as Unconfirmed in this article.
Browse all items first if you’re planning a mobility-focused run. Feathers is a movement item that increases jump height and mid-air distance, helping you traverse high platforms, reposition above swarms, and grab airborne pickups more safely.
Why Feathers + Scarf? Feathers gets you airborne more easily and for longer; Scarf increases damage while airborne (buffed in v1.0.17 from +33% to +50%).