Hyrule Compendium Entry
Armored Carps are a type of Fish found in bodies of freshwater throughout Hyrule. Large deposits of calcium within their scales cause their scales to be as hard as armor. Because of this, cooking them into a dish will grant the consumer a boosted defence.
Like all fish within Breath of the Wild, Armored Carps can be caught by Link. Once caught, they can be eaten raw to restore one Heart worth of health, or they can be cooked or frozen to gain more Hearts and Effects upon consumption. When Armored Carps are combined with any other ingredient, they will cause the dish to develop a tough effect.