Silumgar

Silumgar is one of the five elder dragons of Tarkir. He is a fat, snake-headed creature with a corrosive, venomous breath that hoards valuable items. He is destructive, cruel, and murderous.

Silumgar's Brood
Silumgar and his brood emerged full-fledged from Ugin's dragon tempests and were drawn to Tarkir's misty jungles and swamps, stealing treasure and spreading death everywhere.

Original timeline
Silumgar and his brood were revered by the Sultai Brood for their ruthlessness. After Ugin's death, they lost the battle against the clans of Tarkir. No new brood was created and all died. Silumgar never reached elder status and died in the river Marang near the Molderfang Falls. There, he was killed by a young and cruel Sultai khan (likely Tasigur) and the place became a holy site for the Sultai.

Alternate timeline
In the new timeline, the Sultai khan Tasigur offended the Rakshasa and the Nagas, prompting them to abandon the clan, forcing them thus to make a pact with Silumgar and his brood. Tasigur later betrayed the other khans by revealing to the location of their meeting, under the promise of a special place of power under Silumgar's regime. His 'reward' was to become a pet for Silumgar to display his dominance over. 1280 years later, Silumgar still wore Tasigur's body as a pendant.

Clan Silumgar
Of the five dragonlords on Tarkir, Silumgar has the fewest living followers, but the clan's undead numbers are unrivaled. Silumgar's underlings emulate their dragonlord in all that they do. They take care to curry favor and deflect blame. Assassination and extortion are commonplace as those in the inner circle jockey and kill for a position. The naga translators are often the first and fastest to gain favor. They are also the first to abuse what they have earned. When Silumgar wants to lay waste to his enemies, he calls on the Deathbringer dragons. They breathe clouds of poison gas that choke armies and drool streams of acid that dissolve everything in their path. Meanwhile, some necromancer dragons can enhance their terrible magic by pulling the latent energy from dead flesh.

The dragonlord himself has grown paranoid about losing everything he has gained to Kolaghan or that the Rakshasa might turn against him as they did with the Sultai. In these fits, he often kills his own subjects. When he discovers that someone has attempted to undermine or manipulate him, his answer is often swift and brutal, rooting out whole networks to punish sedition. As a result, numerous festivals and rites are designed to distract, soothe or delight the dragonlord and keep his thoughts away from paranoia.