Haagenti is the Demon Lord of Alchemy and Change.
He is seen by some as the most reasonable and least destructive of the demon lords due to his numerous helpful creations, the most famous being the philosopher's stone which transmutes lead into gold, and this wondrous item is used as his unholy symbol.
This perception of his urbanity is, in fact, a deliberate ruse: Haagenti is just as evil and destructive as any other demon, but more subtle than most.
His wondrous alchemical devices, although seemingly beneficial, are only granted to those who would employ them for evil and destruction.
Haagenti's other creations include alchemist's fire, the demonic retriever, and the secrets of the drow's fleshwarping magic.