Armor Class 20
Hit Points 67 (9d8 + 27)
Speed 30 ft., fly 30 ft.
Skills Perception +4
Damage Immunities necrotic, poison
Condition Immunities blinded, charmed, deafened, exhaustion, frightened, paralyzed, petrified, poisoned, stunned
Senses Blindsight 60 ft., passive Perception 14
Languages understands Common plus one other language but can't speak
Challenge 4
Magic Resistance. The helmed horror has Advantage on saving throws against spells and other magical effects.
Spell Immunity. The helmed horror is immune to three spells chosen by its creator. Typical choices include Heat Metal, Lightning Bolt, and Magic Missile.
Multiattack. The helmed horror makes two Arcane Sword attacks.
Arcane Sword. m +6, reach 5 ft. Hit: 8 (1d8 + 4) Slashing damage plus 5 (1d10) Force damage.
Monster Manual (2024), p. 166