SRD (p.339)
Confer Fire Resistance. The nightmare can grant Resistance to Fire damage to a rider while it is on the nightmare. Illumination. The nightmare sheds Bright Light in a 10-foot radius and Dim Light for an additional 10 feet.
Hooves. Melee Attack Roll: +6, reach 5 ft. Hit: 13 (2d8 + 4) Bludgeoning damage plus 10 (3d6) Fire damage. Ethereal Stride. The nightmare and up to three willing creatures within 5 feet of it teleport to the Ethereal Plane from the Material Plane or vice versa.
| d6 | The Nightmare Carries... | 
|---|---|
| 1 | The champion or messenger of an evil deity. | 
| 2 | A group of joyriding Imps or Quasits. | 
| 3 | An innocent soul trapped on the wild Fiend. | 
| 4 | A lore-hunting Mage, Cultist, or Lich. | 
| 5 | A Night Hag herding larvae between planes. | 
| 6 | A wicked cavalier, such as a Death Knight, an Erinyes, an Incubus, or a Vampire. | 
Planar (Lower Planes)