Gloomstalker

Gloomstalkers are flying monstrosities native to the Shadowfell.

Appearance
Gloomstalkers are black, swirling shadows with little discernible details that loosely assembled into a solid body, resembling a wyvern. They have an elongated neck, two bright, greenish-yellow eyes, and smokey wings, robbed of their skin or flesh. When they flap, the wings leave trails of curling bits of black smoke. As well as a wyvern, they are about 20 feet from wingtip to wingtip.

Behavior
The gloomstalkers are able to gather and coordinate in packs, commonly consisting of three to six specimen, but sometimes growing into larger packs of ten or more, called frenzies. They are able to communicate with one another and obey commands given via Dominate Monster.

Due to their sunless origig in Shadowfell, gloomstalkers have propensity for darkness, which makes them extremely dangerous at night or in heavily shaded places where they can blend in with their shadowed surroundings.

One of the gloomstalkers encountered by Vox Machina showed evidence of being able to dispel an illusion of a little girl, produced by Scanlan. However, the gloomstalker was not intelligent enough to understand why the little girl disappeared when its anti-glamor cone crossed her.

Gloomstalkers are sexless.

Abilities
Gloomstalkers are vulnerable to radiant damage and sensitive to sinlight.


 * Shadowstep: As a bonus action, the gloomstalker have the ability to teleport teleport up to 40 feet to an unoccupied space it can see.
 * Shriek (recharge 6): The gloomstalker emits a terrible shriek. Each enemy within 60 feet of the gloomstalker that can hear it must succeed on a DC 13 Constitution saving th row or be paralyzed until the end of the enemy's next turn.
 * Gloomstalkers are able to snatch one medium or smaller creature, dealing slashing and necrotic damage, grappling, and restraining their target.
 * Multiattack: The gloomstalker makes two attacks: one with its bite and one with its claws.

Known gloomstalkers
Gloomstalkers originated in Shadowfell. During the Calamity, they were employed as mounts by arcanists and the followers of the Betrayer Gods, marching into battles. As of 835 PD and 836 PD, Gloomstalkers, in "respectable numbers", hold hidden lairs scattered across the Barbed Fields of Xhorhas.

-
Vox Machina encountered gloomstalkers in the Shadowfell, patrolling the skies above Thar Amphala. One of the gloomstalkers caught sight of the group as they were crawling under a wall into the city. It grabbed Keyleth, the last one to go through, and pulled her back. Scanlan quickly cast Dominate Monster and took control of it, telling it to release Keyleth and tell the other gloomstalkers that the hunt was off. It obeyed and, after a short discussion, the party named the creature "Mr. Mistoffelees".

Vax'ildan and Scanlan later rode Mr. Mistoffelees up to scout out the ritual taking place atop Entropis.

Arkhan the Cruel took control of a gloomstalker using the Wreath of the Prism to cast Dominate Monster. This creature, dubbed "They" by the dragonborn, became his new mount before he and Vox Machina were attacked by Lord and Lady Briarwood and their own mount: an undead white dragon and previous mount of Arkhan.

After Vecna was defeated and banished beyond the Divine Gate, his gloomstalkers dissipated in clouds of smoke, leaving a black sludge behind.

The Mighty Nein encountered them in the Barbed Fields on their way towards Bazzoxan. The group inadvertently disturbed a group of gloomstalkers when they were eating an udaak they had just killed.

Behind the scenes
Gloomstalkers share a name with a ranger subclass introduced in Xanathar's Guide to Everything, called the "Gloom Stalker".