Fiery Heart
Fiery Heart is worth 375 gp at an NPC and weighs 1.15 oz.
Where to sell
Dropped by
Fire Overlord (always), Hellfire Fighter (uncommon), Hellhound (uncommon), Lava Golem (uncommon), Magma Crawler (uncommon), Vulcongra (uncommon), Weeper (uncommon), Blazing Fire Elemental (semi-rare), Thornfire Wolf (rare), Blistering Fire Elemental.