Sources
CR
Type
Size
Alignment
Movement

Nightmare

Large Fiend, Neutral Evil

Armor Class 13 (natural armor)
Hit Points 68 (8d10 + 24)
Speed 60 ft., fly 90 ft.
STR
18
+4
DEX
15
+2
CON
16
+3
INT
10
+0
WIS
13
+1
CHA
15
+2
Damage Immunities fire
Senses passive Perception 11
Languages understands Abyssal, Common, and Infernal but can't speak
Challenge 3 (700 XP)

Traits

Confer Fire Resistance. The nightmare can grant resistance to fire damage to anyone riding it.

Illumination. The nightmare sheds bright light in a 10-foot radius and dim light for an additional 10 feet.

Actions

Hooves. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit:13 (2d8 + 4) bludgeoning damage plus 7 (2d6) fire damage.

Ethereal Stride. The nightmare and up to three willing creatures within 5 feet of it magically enter the Ethereal Plane from the Material Plane, or vice versa.

Lore

A nightmare appears in a cloud of roiling smoke, its mane, tail, and hooves wreathed in flame. The creature's unearthly black form moves with supernatural speed, vanishing in a cloud of brimstone as quickly as it appeared.