The key item of the Wing Dungeon is the Roc's Feather. This item allows Link to jump over small gaps, enemies, and projectiles. It's an incredibly versatile tool for both combat and puzzle-solving. You'll typically find it in a chest after defeating the dungeon's mini-boss. Once obtained, equip it to an action button immediately.
The Roc's Feather is essential for navigating the Wing Dungeon's many pits and obstacles. It also provides a significant advantage in combat, allowing you to dodge enemy attacks more effectively and even jump over some enemies entirely. Practice jumping over single-tile gaps and using it to avoid projectiles. This item will be indispensable for the remainder of your adventure, opening up many new areas and strategies.