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
Common and Infernal but can't speak
Challenge
3 (700 XP)
Proficiency Bonus
+2
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.
So is it possible to have one as a mount? That would be cool.
that depends on your GM
Ethereal Stride best ability!
It would make sense for a warlock, especially an infernal or abbisal one. Maybe with a summoning spell.
The best mount
Definitely up to the DM, the description does say they do not appear naturally and are instead created through a ritual that involves tearing the wings off a pegasi and turning it into a Nightmare. So there's already info on how they're created, and players can already use pegasi as mounts through spells like find greater steed, then it's up to the DM to decide whether or not the knowledge of the ritual are shared with the PCs :)
You can if you find https://www.dndbeyond.com/magic-items/figurine-of-wondrous-power-obsidian-steed one of these.
The mount summoned by Find Greater Steed is just a spirit that takes the form of the mount you choose. Tearing off the spirit's wings (if possible) wouldn't transform it into a nightmare (specifically) or a fiend (generally). Except for DM homebrew fiat, of course.
Oh good point, I hadn't realised that, thanks!
The Infernal Tack magic item
play curse of strahd, and steal his, im sure that'll go well :D
Why does it have flying speed?
https://www.dndbeyond.com/magic-items/figurine-of-wondrous-power-obsidian-steed
Because it can fly.
HOW??!?
Nightmare pegasus.
Wings were torn off tho
I got one in Avernus for getting the infernal tack off of a boss I practically solo'd. Almost died in a very bad way but didn't and it was 100% worth it.
Fire hooves that makes him walk through the skies.
Or simply put, Its magic.
Yes. In the new module Descent into Avernus there is an opportunity to do so.