Trivia: Kulve Taroth's golden appearance are actually related to their habitat. Kulves has high internal body temperature, and they used that to melt ores and metal-bearing rock, causing it to drip on their body and creating outer layer of metal.
They use this metallic layer as heat sink, dissipating their body temperature. Kulves' reason to use gold might not only because it is highly malleable, but the low melting point gives it the ability to mollify; means it can be transformed to semi-liquid state that will absorb impacts, or shed easily when the gold layer became too thick and heavy to be carried around.
Once in a while, you might find some relics encased on gold when the gold mantle breaks. It was thought that these relics are weapons of Hunters of past age, which became embedded in Kulve's gold mantle during the process of mollifying and stuck there, became plated in gold. Those could be salvaged and reshaped into proper weapon by a skilled blacksmith, and it was said after being encased in Kulve's gold for so long, the weapon exhibits some wonderful properties. These relics, paired with the dragon's golden-encrusted appearance, made Hunters nicknamed this dragon 'Treasure Dragon', because it is a literal walking treasure trove.