Death Dragon

"What fear is greater than that of death to all one holds dear?"

- Myasindos belittling Abbadon, Lord of Fear

Origin
In an ancient time, the land that would later be Equestria was ruled by the Dragon Lords of Sibaalbuat, six brothers who had mastered the forces of nature and used their power to conquer and partition the continent. The eldest of these brothers, Myasindos, claimed mastery of death and kingship of the southern barrens where the changelings now reside. The Anugyptian jackals who dwelt in the land at this time suffered under the dragons' rule and conspired to imprison them in Tartarus. They succeeded, making the six Dragon Lords some of the nightmarish realm's first permanent inhabitants.

However, recently, Professor Ahmet Abmule inadvertently brought the Anugyptians' "lock tablet" to the ruins of the Death Dragon's lair, enabling Myasindos to exert his remaining power on the relic and dissolve the seal keeping him and his brothers confined. They then proceeded to terrorize the eastern coast of Equestria, particularly Fillydelphia, until a new hero who had unintentionally absorbed the power of Melanthios the Fire Dragon dared to challenge them. Despite their best efforts, this hero managed to divide and best them, imprisoning them again within golden tablets from the olden days. For a second time, they were sent to Tartarus.

Yet one of the Death Dragon's bony feet had not been with him at the time of his capture. He guided the foot down to the dragons' prison and carved out instructions for his brethren. A year later, the combined power of all six managed to shatter the Death Dragon's tablet and launch his remains through the earth and into hell. From the castle of the Lord of Fear, he then returned to Equestria via the cemeteries of Fillydelphia.