With scales the color of the desert sky, this large, serpentine dragon moves with an unsettling grace.
5e SRD
A proud, ancient race of gigantic, carnivorous, winged reptiles. There are many subspecies of dragon, many of which are distinguished by the colour of their scales. All dragons are egg-layers and hoard treasure in their lairs, far from areas of human civilisation.
OSE
Deadly desert-dwelling dragons that attack with lightning breath
The deserts of the southern lands are home to the deadly blue dragons. These creatures dwell in vast caves in arid lands coming forth to visit their enemies and innocent victims with deadly lightning attacks.
Blue dragons often (60%) are known to speak, only sometimes (30%) cast magic, but sometimes will (30%) be found asleep. If the dragon is asleep, there is a 1 in 6 chance that it will awaken in the presence of adventurers. Dragons also sometimes feign sleep.
If a blue dragon can cast spells, it gains spells as if it were a wizard of a level equal to its age category.
OSRIC