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)

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.

Running this fight? Add the nightmare to the initiative tracker: type its name and the AC, hit points and initiative bonus fill in, and the book button shows this stat block mid-fight.