Festule the Alchemist

Festule the Alchemist is an alchemist who sells a potion to incapacitate an ogre. He only appears during the quest Mazzy has challenged Gorf the Squisher. The party can buy the potion to drug Gorf when he's fighting Mazzy in the pit. The party must buy his potion before talking to Bunkin. The price is 500 GP, but the party can buy it for 400 GP.
Talk to Bunkin and persuade her to let Gorf drink the potion before the duel.