Dungeon Crawl Classics #16: Curse of the Emerald Cobra

Remember the good old days, when adventures were underground, NPCs were there to be killed, and the finale of every dungeon was the dragon on the 20th level? Those days are back. Dungeon Crawl Classics don't waste your time with long-winded speeches, weird campaign settings, or NPCs who aren't meant to be killed. Each adventure is 100% good, solid dungeon crawl, with the monsters you know, the traps you fear, and the secret doors you know are there somewhere.
Centuries ago, a seemingly immortal yuan-ti warrior known as Xiuhcoatl, the Emerald Cobra, ruled over the vast Eztenqui Jungles with an iron fist. Finally, a wizard managed to end the evil serpent's reign of terror by trapping its life essence in a magical staff. The staff became both the figurative and literal heart of Voltigeur, resting in an enchanted case in the center of the town as a symbol of victory. But now the magic staff has vanished. Since the disappearance, merchant caravans traveling to Voltigeur have been savagely attacked. The few survivors report that their attackers were serpent-men swearing fealty to the reborn Emerald Cobra! Legends speak of an old pyramid near Mount Icpitl that was once the Emerald Cobra's palace. Can the heroes locate this ancient ruin and destroy the reborn Emerald Cobra?