Dragons

In answer to the celestials' giants, Evil incarnated in the form of Tiamat, seduced the titan Abzu to steal the gift of Life, and gave birth to the first five chromatic dragons (red, blue, green, black, and white) whom she sent to destroy all that the giants built. Though fully-willed, chromatic dragons are generally evil.

Life, enraged that her gift had been twisted to create evil creatures, decided to return the favor and seduced Tiamat to conceive the first five metallic dragons. Metallic dragons are generally good, but they are still quite dangerous and are no friends to the giants, who tend to treat all dragons as enemies. In my world there are no bronze or brass dragons, being replaced by tin and zinc dragons respectively.

Gold, silver, copper, tin, and zinc are called the five draconic metals, all sources of them come from dead metallic dragons, who's scales may break apart but never decay. Metallic dragons, possibly due to sensitivity about their ancestors bodies being passed around by other species, tend to horde these metals.

Dragons tend to be highly antisocial, but have respect for their relatives. They only have one child at a time, but they  are hermaphroditic so occasionally two dragons will impregnate each other resulting in twins. Dragons generally have the same color as their mother. Dragons are immortal and never cease growing. This forces them to eat which often puts them in conflict with other races, so dragons will often choose to enter a deep meditative state where they do not eat or grow, and stay in that state for centuries or millenia.