Fish Scale

The Fish Scale, also known as Fish 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 Fish Fin is a Guardian Force-affinity boost item. It can also be used for refining.

Final Fantasy X
Fish Scale is an item for the Use command that can also be used to customize Waterstrike to weapons.

Final Fantasy XI
Fish Scales are used mainly for bonecrafting.

Final Fantasy XII
The Fish Scale is loot that can be acquired from Danbania, Bull Danbania, Ichthon, Apsara, Rain Dancer, and Razorfin. Two may be sold toward unlocking the Marksman's Delight at the Bazaar. A Fish Scale may be sold for 151 gil.

Dissidia 012 Final Fantasy
The Fish Scale and Delicious Fish Scale are trade accessories. Their names and descriptions refer to Final Fantasy VI when Celes had to catch fish to nurse Cid back to health.