Sources
CR
Type
Size
Alignment
Movement

Oread

Medium Fey, Chaotic Evil

Armor Class 16 (natural armor)
Hit Points 49 (9d8 + 9)
Speed 30 ft.
STR
14
+2
DEX
14
+2
CON
12
+1
INT
11
+0
WIS
13
+1
CHA
18
+4
Skills Acrobatics +4, Athletics +4, Performance +6
Damage Immunities fire, poison
Condition Immunities Charmed, Frightened, Poisoned
Senses passive Perception 11
Languages Common, Sylvan
Challenge 4 (1,100 XP)

Traits

Invisible in Fire. The oread is invisible while fully immersed in fire.

Magic Resistance. The oread has advantage on saving throws against spells and other magical effects.

Spellcasting

Innate Spellcasting. The oread's spellcasting ability is Charisma (spell save DC 14, +6 to hit with spell attacks). It can innately cast the following spells, requiring no material components:

At will: fire bolt (see "Actions" below)

1/day each: hellish rebuke (see "Reactions" below), scorching ray

3/day: burning hands

Actions

Multiattack. The oread attacks twice with its fiery touch or fire bolt.

Fiery Touch. Melee Spell Attack: +6 to hit, reach 5 ft., one target. Hit:9 (1d10 + 4) fire damage.

Fire Bolt (Cantrip). Ranged Spell Attack: +6 to hit, range 120 ft., one target. Hit:5 (1d10) fire damage.

Reactions

Hellish Rebuke (2nd-Level Spell; 1/Day). When the oread is damaged by a creature within 60 feet of the oread that it can see, the creature that damaged the oread must make a DC 14 Dexterity saving throw, taking 16 (3d10) fire damage on a failed save, or half as much damage on a successful one.

Lore

Aggressive oreads number among the most dangerous nymphs, as they embody the wild might of flames, volcanism, and the hidden forces of the earth. These creatures typically dwell in remote mountain crags and near volcanoes, where they caper among the forces of dissolution and rebirth. During avalanches and volcanic eruptions, groups of oreads might race ahead of the destruction, dancing, singing, and doing what they can to maximize the impending devastation.