Medium elemental, neutral

Armor Class 14
Hit Points 61 (10d8 + 16)
Speed 0 ft., fly 60 ft. (hover)

12 (+1) 19 (+4) 14 (+2) 6 (-2) 13 (+1) 11 (+0)

Saving Throws Dexterity +7
Skills Perception +4, Stealth +7
Damage Resistances cold, lightning, thunder; bludgeoning, piercing, and slashing from nonmagical attacks
Damage Immunities poison
Condition Immunities exhaustion, grappled, paralyzed, petrified, poisoned, prone, restrained, unconscious
Senses darkvision 60 ft., passive Perception 14
Languages Niln
Challenge 5 (1,800 XP)

Special Traits

  • Gaseous Form. The niln can enter a hostile creature’s space and stop there. It can move through a space as narrow as 1 inch wide without squeezing.
  • Drowning Fog. As a bonus action, the niln can fill the area within a 30 ft. radius of it with a cold, semi-solid fog. This area is difficult terrain and heavily obscured for all creatures except nilns until the start of the niln’s next turn, and any creature in the affected area is unable to breathe unless it can breathe water.


  • Multiattack. The niln makes two Slam attacks.
  • Slam. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) bludgeoning damage.
  • Drench. All nonmagical, open flames within a 30 ft. radius of the niln are extinguished.


Niln hail from a plane made of air and water; a vaporous and saturated realm known as the Quasi-Plane of Vapor. They are normally docile creatures, but are quick to anger, and relentless in their attack.

Like many elementals, niln are most at home on their native plane and rarely leave it. They sometimes travel the Elemental Planes of Air when not traveling through their own realm, but usually do not enter other planes unless summoned. Should one find itself on the Material Plane, it seeks to escape and return to its home plane unless confined or summoned by a spellcaster. Assigned tasks are completed to the best of the niln’s ability and they rarely ask for much of anything in return. On the Material Plane, a niln seeks sources of vapor or steam in which to bathe its form so they are almost always encountered in such areas.

When first confronted, a niln surrounds itself with its drowning fog to deter would-be-aggressors. Those that insist on entering the fog and attacking the niln are met by its physical attack; the niln forms wispy tendrils from its form and lashes out at its foes. A niln will use its drench ability to extinguish any source of light its aggressors may be carrying, relying on its darkvision to aid it in the darkness thus created.

Section 15: Copyright Notice

City of Brass ©2018 Frog God Games; Authors: Casey Christofferson and Scott Greene