Zehir

Zehir, the Cloaked Serpent is a god of poisons, assassins, and darkness. He is the creator of snakes and also of yuan-ti. Most of his followers were annihilated during the Calamity, and those who survived are in self-induced stasis or hunted by the followers of the Spider Queen and the Crawling King.

Appearance
Widely-known depictions of Zehir found in his ancient temples, portrays him in a man's body with a half-dozen arms and a gargantuan fanged serpent head, with strands of thick, dark hair sprouting from his scaled body that swirl around to form layers of shadow, obscuring his entire form.

Pre-Divergence
Zehir is one of the Betrayer Gods who, during the Founding, chose the side of the Primordials and the mortal races from Exandria and starting fresh elsewhere. To the the conclusion of the conflict, the Betrayer Gods were banished by the Prime Deities to prison-like planes, sealed behind the Divine Gate. Though it's unclear to which plane Zehir was banished at that time.

Just before the Calamity, followers of Zehir slaughtered the people in the Vault of Shumas and locked it off. Similarly, seers of a serpentfolk empire, who worship Zehir above all deities, foresaw the Calamity. To survive its dangers, the empire created a magical stasis field under their capital city of Vos'sykriss, where its strongest people waited to one day emerge and rebuild their empire.

During the Calamity, Zehir ambushed and killed many of Melora's followers near one of her shrines in the Lushgut Forest. Melora's anguished scream altered the forest, making it tortuous and thorny.

Post-Divergence
The Mighty Nein encountered Zehir, when they pursued servants of Uk'otoa to the location of the final seal to a temple of Zehir in the Cyrios End Forest. Zehir spoke to them through a statue, preventing them from leaving until one of them made a pact to prove they intended to hunt down and reseal Uk'otoa. Kingsley initially volunteered, but Fjord ultimately made the pact, saying it was his responsibility. In return, Zehir branded him with the power to seal Uk'otoa and granted him the Fang of the Spire King, a rapier, which Fjord gave to Kingsley.

After the Mighty Nein defeated Uk'otoa and Fjord sealed it, Fjord was briefly able to feel his pact with Zehir before Melora removed it.

Relationships
The Cloaked Serpent loathes the Lawbearer and the Wildmother, as they stand for everything he despises: love, order, and life. His followers try to appease him by using poison and fire to undermine civilization and consume nature.

Uk'otoa
The Cloaked Serpent is the creator of Uk'otoa, the Great Leviathan. After Zehir was banished during the Calamity, Uk'otoa was left to rule the Lucidian Ocean as his proxy. However, Uk'otoa began demanding that people who entered his domain renounce their gods and worship him, which enraged Zehir. To punish Uk'otoa's insolence, in the fifth century PD it was cultists of Zehir who corrupted a series of temples dedicated to Uk'otoa and sealed the leviathan deep beneath the ocean floor.

In one of these temples on Urukayxl, the Mighty Nein saw three murals depicting Uk'otoa, Desirat, and Quajath. The three lesser idols have a pact, if one escapes, it will help the others, so presumably Zehir is an antagonist of Desirat and Quajath as well.

Worship
The tenets of Zehir's religion are largely related to the sowing of chaos and the majority of his following includes serpentfolk, also known as yuan-ti).

Artifacts
Before the Calamity, Zehir and the other Betrayer Gods each forged one of the Arms of the Betrayers, sentient weapons using the life force of greater fiends. Zehir's weapon was the Lash of Shadows, is a whip with five serpent heads, within which is the life force of a marilith called Sizlifeth.

Places of worship
Many temples were built to Zehir, but were lost to time when his following was largely culled.

The Mordant Isle
Off the coast of the Tooth of Zehir is the Mordant Isle. On the island, the ruins of Sariss, the Jade City, are home to a colony of winged serpentfolk who worship Zehir.

The Vault of Shumas
In the Aggrad Mountains of Marquet, there was a hidden temple guarded by yuan-ti, a manticore, and an undead spirit calling herself "the caregiver". The caregiver watched over the sleeping children of Zehir "until our epoch begins."

Urukayxl
On the island of Urukayxl in the Lucidian Ocean, there is a large five-sided pyramid that serves as a temple to Zehir. The pyramid and its surrounding village were largely populated by yuan-ti.

Cyrios End Forest
One of the seals of Uk'otoa was within a temple in the Cyrios End Forest. The temple is decorated with dangerous sigils of the sun, and inside the temple are hundreds of snakes. There is also a carved stone mural depicting a Calamity-era battle of sea serpents attacking a navy, and a statue of Zehir. The temple was heavily damaged by Thoonum and by Jester's Earthquake spell.

Appearances and mentions

 * Campaign 2
 * Campaign 3
 * One-shots
 * Campaign 3
 * One-shots
 * One-shots
 * One-shots

Trivia

 * Matt confirmed in that the three entities pictured in the yuan-ti temple, including Uk'otoa, are all creations of the gods. He said some creations of the gods became "pseudo-gods" after being left behind by their creators.
 * "Zehir" means "venom, poison" in Turkish.