What Strange Creatures...

I am interested in learning more about the strange reptiles that mill about the lava flows of Shadowmoon Valley. Never have I seen beasts able to withstand the searing heat of molten lava!$B$BOutside of Shadowmoon Village, where the ground has ruptured and lava flows through the cracks, you will find felfire diemetradons. Slay them and bring me their spleens. From their spleens I will be able to begin preliminary analysis of their resistance to heat.$B$BBegin your search to the southeast.$B