Origin: Persian Mythology, Shahnameh: The Persian Book of Kings
Dragons Slain: An unnamed dragon of the mountains
Background: Sekandar was the king of Persia. He lead his army by ship to a land where people have soft feet. Their numbers were great and each man stood 'tall as a cypress tree.'  Yet among the strange warriors, not a single horseback rider nor swordsman stood, and none carried maces, like the soldiers in the Persian Army. 
When the soft-footed warriors attacked, they did so without armor or clothing, and their war cry was as a roll of thunder. They threw stones as hail from the sky. Sekandar's troops fought with both arrows and swords, and they battled the naked warriors till dust misted around them. When only a few of their enemies remained, Sekandar took his army to rest and then moved out to find a proper campground. 
As the army moved out, they found a city of profound size and population, the likes of which Persia had not seen before. The people within were friendly and sent messengers with food and gifts to welcome the army. Sekandar, being of sound mind, treated the people cordially. Soon the town set aside parts of a nearby plain for the army to make camp, so there was no attempt to raid the city. 
Sekandar, the Dragon Slayer
Nearby the army encampment stood an enormous mountain; those that were on the mountain during the day did not stay there for the night. Sekandar approached the locals and asked for a route for his troops. Those that responded seemed fearful, and they explained that the only way inland was to pass through the mountain.
No one used the mountain pass, for there lived a terrible dragon of such strength and power that no one could pass the mountain. Even the city, with its great size and resources, failed to fend off the dragon. Instead, they placated it, and each night they brought the dragon five cows. 
The locals described the dragon as thus:
His poison sickens birds that venture there,
The noxious vapors reach the moon, there's no
Safe route by which your warriors could go.
His massive maw breathes fire, and he could snare
An elephant with his two locks of hair...
-- Shahnameh, Firdowsi, translated by Davis 
Sekandar asked the locals not to feed the dragon the next day, and they agreed. The next day, when the dragon's feeding time had long passed, he perched on the slope of the mountain and breathed a tremendous burst of flame.  Sekandar ordered a hail of arrows to be shot at the beast, and the creature caught the arrows with its fiery breath  and killed some of the archers. Sekandar ordered the war drums, and the dragon fled for fear of the echoing sound. 
The next day, Sekandar planned a different attack. He men to purchase five cows, which were then killed and skinned, leaving the heads attached to the hides. He filled the hides with poison and oil, inflating them so they appeared to be slaughtered cows. As Sekandar and his troops brought the cows up the mountainside, they prayed. They arrived after the appointed feeding time, and the dragon, now having gone a day without food, furiously waited on the mountain. 
As Sekandar looked upon the mighty monster, his foe, he saw that the dragon was 'like a huge dark cloud: his tongue purple, his eyes blood red, and fire issuing continuously from his maw.'  So the selected soldiers rolled the cow carcasses down towards the dragon, and waited with prayer to see what the dragon would do. 
The dragon swooped down and gulped up the carcasses, unaware of the poison and oil, which quickly spread. The poison burst his intestines, and spread to every part of his body, from his feet to his brain. The dragon thrashed helplessly in desperation, and the troops sent another hail of arrows at him. Finally, the dragon died of both the poison and the arrows. Sekandar left the beast's body and moved his troops out. 
- Sekandar, King of Persia, led the Persian Army into battle. 
- After they defeated their first enemy, they befriended a local city near their encampment. 
- The only route inland was through the nearby mountain, which was the abode of a horrific dragon. 
- The local city could not defeat the dragon; instead, they placated it with five cows a day. 
- The dragon breathed flame and poison. 
- Sekandar first ordered that nothing be brought to the dragon in attempts to draw it out. When this happened, the first attempt to kill it with arrows failed, and resulted in the death of a few archers. 
- The next day, Sekandar took slaughtered cows and filled their hides with poison and oil. They appeared to be the dragon's normal placation. 
- The dragon ate up the poisonous cows and writhed helplessly in pain. Volleys of arrows hit the dragon, till at least it died. 
- Sekandar left the body and moved his army inland, the only obstacle defeated. 
- Firdowsi [Shahnameh Trans. Davis] 506
- Firdowsi [Shahnameh Trans. Davis] 507
- Firdowsi [Shahnameh Trans. Davis] 508
For more information on footnotes and references, please see the bibliography.