Genshin Impact

Tusk of Monoceros Caeli

The horn of a whale that you obtained from defeating Childe, who had unleashed the might of his Delusion.
It is said that the shape of one's constellation determines one's character. The image of a whale cruising across the celestial heights represents a solipsism that seeks to crush and devour all in its path.
Embracing this aspect of himself, Childe gleefully summoned one such beast before throwing himself into battle against you.