Cloak of the Bat

While wearing this cloak, you have advantage on Dexterity (Stealth) checks, and in areas of dim
light or darkness, you can use your action to cast polymorph on yourself, transforming into a bat
for 10 minutes, retaining your non-physical stats.
A 6th level or higher character can grip the edges
of the cloak with both hands and use it to fly at a
speed of 40 feet. If you ever fail to grip the
cloak's edges while flying in this way, you lose
this flying speed.