Volcano Spawn is a level 36 monster found in the Volcano Entrance. They have 28,321 health points and 500 MP though they do not seem to use the mp to cast spells. Using melee attacks they can do 985 damage and they have 653 defense. Using a mixture of the Spy skill and trial and error it appears they can drop the following items at the following percents.
Fire Core drops at a 0.1% rate
Draconian Essence drops at a 2.5% drop rate
Level 30 armor seems to drop at a ~ a 2.5% drop rate (this does not show up on Spy.)