The Caged Nightingale was a magical nightingale in a gilded cage. It had been stolen from Milvia, the little old lady who lived in the Antique Shop. Graham covered the cage with the Cloth to quiet the bird, so Hagatha wouldn't be alerted by its singing. He took the cage out of the cave. He later gave the bird to little old lady, who then gave him the Oil Lamp in thanks.
Behind the scenes
This item can be described as simply the "cage" or the "bird", or nightingale. In the official KQ2 hintbook this item is known as the 'Nightingale in cage'.
If you open the cage, the bird will escape, leaving the Empty Birdcage.