Wings of Flying

From Dungeon Master's Guide, page 214. Found on Magic Item Table G.

Description
Wondrous item, rare (requires attunement).

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.