"You got the Moon's Tear! Its sparkling beauty radiates rather strangely."
— In-game description

The Moon's Tears are items from The Legend of Zelda: Majora's Mask. They are lunar rocks that have fallen from the eye of the Moon, and were thus dubbed "Moon's Tears" by Shikashi, the owner of the Astral Observatory. With their distinctive blue glow, they are valued by the inhabitants of Clock Town. At one point, the Skull Kid threatened to steal the Moon's Tear which Shikashi has on display.

After Link uses the telescope to gaze at the Skull Kid atop the Clock Tower, a Moon's Tear crashes down into the platform outside the observatory. It can be traded to a Business Scrub in South Clock Town for the Land Title Deed, giving Link the right to use the Deku Flower. Link must use this flower to access the top of the Clock Tower on the Final Day in his Deku form, and can also use it to reach several treasure chests. After completing the first three day cycle, Link will regain his Hylian form, and can easily climb to the entrance of the Clock Tower without needing to find and trade the Moon's Tear.