The Stockwood Scrolls
Some dragons have the power to polymorph into other forms, and when such a dragon mates with another creature in polymorphed form, the union sometimes produces half-dragon offspring. A creature might also transform into a half-dragon as a result of a mad wizard’s spell or a ritual bath in dragon’s blood. In all these cases, the result is a creature that combines the essence of a dragon with the form of its original race.
Half-dragons inherit personality traits common to their draconic heritage, so that half-gold dragons are often shy and secretive, while half-copper dragons are impish and playful. Half-green dragons are deceitful, while half-white dragons are often dim-witted brutes. These traits are tempered by a half-dragon’s other lineage, but greed, arrogance, and paranoia are qualities that even good-aligned half-dragons often possess.