Each of the Item-slot items dropped by the Avatars which are used in the Mama Mia quest were a Key Item from one of the first seven Final Fantasy games. Bubbly Water (called Oxyale in the original English translation) was a key item in Final Fantasy required for the party to breathe underwater, a necessity when exploring the Sea Shrine, the location of Kraken, the Fiend of Water. Oxyale was found in a spring in the woods of the remote town of Gaia, but only the Fairy of the pond could give it to you, and she was taken captive by a trader traveling in a Caravan.