Dragon Scale

The Dragon Scale, also known as Dragon Fin, is a recurring, single-use item in the Final Fantasy series that frequently is used to cause some form of Water damage to one or more targets.

Final Fantasy VIII
The Dragon Fin appears as a Guardian Force-affinity boost item.

Final Fantasy X
2 Dragon scales will teach an aeon the blk magic ablity Watera

Final Fantasy XII
The Dragon Scale appears as a Key Item obtained by giving the Viera Rucksack to the Viera Wayfarer after defeating Vyraal. The Wyrm Philosopher from the Cerobi Steppe will trade the Dragon Scale for the Age Worn Key, that will open the Hall of the Wroth God located in the Sochen Cave Palace, where the Hell Wyrm awaits.