Cryvain

Actions

Multiattack. The Cryvain makes an attack with its Slash and one with its Numbing Breath. Slash.Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 5 (1d6 + 2) slashing damage.   Numbing Breath. Ranged Spell Attack: +2 to hit, reach 10 ft, one creature. Hit: 4 (1d8) cold damage.  

Cryvain are winged, ivory-white creatures with a snake's tail in place of legs. Their faces are blank and smooth, except for a jagged maw that they open on rare occasion to belch breaths of deadly cold. Their arms end in hands with fingers like knives that open flesh just as well.
Eerie and Remorseless. Cryvain never make a noise until the moment of their death, when they let out an ear-splitting shriek and collapse into dust and snow. Their gaunt, eyeless faces are unnerving to the bravest of adventurers, and when they attack they do so relentlessly and silently. Pain and exhaustion are of no concern to them, and they are unceasing unless in the face of certain death. While certainly intelligent, they have never expressed any interest in negotiation.
Birds of a Feather. When they can, Cryvain gather into flocks in order to make up for their individual weakness. These flocks are often headed by one or more Seraphim, and on the occasion of a Demiurge's rise they gather into flocks so huge as to blot out the sun. They detest heat more than light, and rarely do they venture very far towards the equator.
Once Divine The origins of the Cryvain are unknown but almost certainly divine in origin. The two current leading theories are that the Cryvain are 1) part of a great group of divine punished for some unforgivable sin or 2) that they are self-aware splinters of a dead god's flesh, buried under the glacial ice. Both seem equally viable at this time.  

Cryvain are only encountered in the harsh, cold places of the world.