Give this pearl to your adult Ryukoi to change it into its Ascended Ryukoi form.
The Ryukoi Pearl can be used on adult Ryukoi. Doing so will turn the creature into its alternate form, the Ascended Ryukoi form. Once changed, the Ryukoi cannot be changed back to its normal form.
On the inventory page, the Ryukoi Pearl is listed as a Transformation item, a trait it shares with the Enchanted Sock. However, since its effect is identical to that of a potion, it can be considered a potion.