Spread life and death.
Henzell says...
  1. Body armour sometimes dropped by {dragon} monsters. Types in order of ascending {encumbrance rating}: {steam dragon scales}, {acid dragon scales}, {quicksilver dragon scales}, {swamp dragon scales}, {fire dragon scales}, {ice dragon scales}, {pearl dragon scales}, {storm dragon scales}, {shadow dragon scales}, {gold dragon scales}
  2. Bone and iron dragons leave no scales.
  3. Prior to 0.20, {mottled dragon scales} existed.

Information based on master branch and the great LearnDB.
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