Large Aberration, chaotic neutral
Armor Class 15
Hit Points 119 (14d10+42)
Speed fly +60, walk +0, hover true
Challenge 9
Saving Throws cha +8, wis +5
Skills acrobatics +8, performance +8
Damage Vulnerabilities force
Damage Immunities cold, psychic, radiant
Condition Immunities exhaustion, grappled, paralyzed, petrified, poisoned, prone, restrained
Senses blindsight 60 ft., passive Perception 12
Languages Void Speech
Incorporeal Movement. The aurora horribilis 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.
Reality Adjacent. The aurora horribilis does not fully exist in physical space. If the aurora is subjected to an effect that allows it to make a saving throw to take only half damage, it instead takes no damage if it succeeds on the saving throw, and only half damage if it fails. In addition, attack rolls against it have disadvantage. A creature with truesight doesn't have disadvantage on its attack rolls, but if that creature looks at the aurora, it must succeed on a DC 16 Wisdom saving throw or be incapacitated with a speed of 0 for 1 minute. An incapacitated creature can repeat the saving throw at the end of each of its turns, ending the effect on a success. This trait is disrupted while the aurora is incapacitated or has a speed of 0.
Multiattack. The aurora horribilis makes two blistering touch attacks.
Blistering Touch. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 15 (3d6 + 5) cold damage plus 10 (3d6) radiant damage.
Void Song. The aurora horribilis creates a dissonant song. Each creature within 100 feet of the aurora that can hear the song must succeed on a DC 16 Wisdom saving throw or be charmed until the song ends. This song has no effect on constructs, undead, or creatures that can speak or understand Void Speech. The aurora must take a bonus action on its subsequent turns to continue singing. It can stop singing at any time. The song ends if the aurora is incapacitated. While charmed by the aurora, the target suffers the effects of the confusion spell and hums along with the maddening tune. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. A target that successfully saves is immune to this aurora's song for the next 24 hours. A target that stays charmed by the aurora's song for more than 1 minute gains one long-term madness.
Source: Tome of Beasts 2 · OGL/Open