DnD 5e Dungeon Master's Guide
Wondrous Item While wearing this cloak, you can use an action to speak its command word. This turns the cloak into a pair of bat wings or bird wings on your back for 1 hour or until you repeat the command word as an action. The wings give you a flying speed of 60 feet. When they disappear, you can't use them again for 1d12 hours. Rare (this item requires attunement)