Tiny undead, chaotic evil

Armor Class 19

Hit Points 22 (9d4)

Speed 0 ft., fly 50 ft. (hover)

STR DEX CON INT WIS CHA
1 (−5) 28 (+9) 10 (+0) 13 (+1) 14 (+2) 11 (+0)

Damage Immunities lightning, poison

Damage Resistances acid, cold, fire, necrotic, thunder; bludgeoning, piercing, and slashing from nonmagical attacks

Condition Immunities exhaustion, grappled, paralyzed, poisoned, prone, restrained, unconscious

Senses darkvision 120 ft., passive Perception 12

Languages the languages it knew in life

Challenge 2 (450 XP)

Consume Life. As a bonus action, the will‐o’-wisp can target one creature it can see within 5 feet of it that has 0 hit points and is still alive. The target must succeed on a DC 10 Constitution saving throw against this magic or die. If the target dies, the will‐o’‐wisp regains 10 (3d6) hit points.

Ephemeral. The will-o’-wisp can’t wear or carry anything.

Incorporeal Movement. The will‐o’-wisp can move through other creatures and objects as if they were difficult terrain. It takes 5 (1d10) force damage if it ends its turn inside an object.

Variable Illumination. The will-o’-wisp sheds bright light in a 5- to 20-foot radius and dim light for an additional number of feet equal to the chosen radius. The will-o’-wisp can alter the radius as a bonus action.

Actions

Shock. Melee Spell Attack: +4 to hit, reach 5 ft., one creature. Hit: 9 (2d8) lightning damage.

Invisibility. The will-o’-wisp and its light magically become invisible until it attacks or uses its Consume Life, or until its concentration ends (as if concentrating on a spell).