Dragon Blood

Dragon Blood (DB) is a magical reagent used in the arts of Thaumaturgy on Pagan.

Pagan
While no dragons appear to be native to Pagan - though statues of them can be seen in Tenebrae, creating the question if they once had been - a reagent known as "dragon blood" is nevertheless available from the sage, Mythran. Whatever this substance's actual origins, it is noted for its burning potency as a magical additive, and adds significant powers to spells crafted with it.

Serpent Isle
In the northern wastes of Serpent Isle, the Gwani make use of the blood of ice dragons for medicinal purposes and employ it to treat the fevered and sick. The Avatar, during their questing in the northlands, would be required to obtain such blood, that the young Neyobi might be cured of her illness.

Earth
Earth legends assign a number of properties to the blood of their mythical dragons, although stories seem starkly divided as to whether the substance is poisonous or curative.

Ultima Online
In the Stygian Abyss expansion for Ultima Online, the Gargish magical school of Mysticism makes use of dragon blood as a reagent.