Black Rocks

The Black Rocks are mysterious sharp rocks that came out of the ground surrounding the spot where the magical flower sprouted form, and later played a part in the return of Rapunzel's long hair.

Background
Sometime before Rapunzel's return to Corona, these mysterious rocks started to sprout out of the ground where the royal guards found the flower that saved the Queen and her unborn child. The only thing that is known about the rocks is that they are unbreakable. Cassandra, brought Rapunzel to rocks while sneaking her out for some downtime. When Rapunzel reached out to touch one of them, a powerful energy burst from the rocks knocked the two girls off their feet and somehow grew back Rapunzel's long hair.

Afterwards, the rocks began to sprout throughout the land. They started to appear around Varian's village, Old Corona. Every time Rapunzel went near them, her hair would glow along with the rocks, indicating that they are somehow connected. Varian promised to help Rapunzel and Cassandra understand the rocks better and to keep their work a secret. As the number of rocks grew started to destroy the village, Varian knew that they would not stop "growing". Once they had destroyed his village they would start making their way to Corona. Varian desperately tried to use alchemy in his attempt stop them, until his experiments got his father "crystalized".

In "The Quest for Varian", Rapunzel has used her hair to interact the rocks and triggered the shockwave to stun the troops chasing her, but it caused the rocks' rapid growth and destroyed the tower consequently. An ancient scroll revealed that the rocks may be caused by the drop of moonlight, with reference of the Magical Golden Flower which comes from the drop of sunlight.