Will-o'-Wisp
Tiny Undead, chaotic evil
450 XP
Special Abilities
Consume Life
As a bonus action, the will-o'-wisp can target one creature it can see within 5 ft. 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 ft. 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).
Quick Reference
Running This Encounter
Will-o'-Wisps are solitary or small groups of malevolent spirits that lure travelers to their doom. Use their Invisibility ability and high AC to frustrate melee-focused parties while their electric attacks punish clustering. Establish the wisp's goal early—protecting treasure, luring victims into danger, or serving a lich—to give the encounter narrative purpose. Remember that wisps can become invisible as a bonus action, making them excellent for ambush tactics.
Combat Tactics
Will-o'-Wisps prioritize ranged attacks from a distance, using their Shock Orb to target spellcasters and fragile party members. They exploit their superior mobility to stay airborne and out of melee range while turning invisible when threatened or after dealing damage. If cornered, they flee using their flight speed and invisibility rather than fighting to the death.
Environment & Setting
Ideal in swamps, marshes, graveyards, and areas near water where the wisp's ethereal nature feels thematic. Encounter works best in areas with difficult terrain or vertical obstacles that complicate pursuit and reinforce the wisp's aerial advantage.