Arnsenon

Large aberration, chaotic neutral

Armor Class 18 (natural armor)
Hit Points 171 (18d10+72)
Speed 15 ft., fly 40 ft. (hover), swim 80 ft.

STR	DEX	CON	INT	WIS	CHA
21 (+5)	16 (+3)	19 (+4)	5 (-3)	14 (+2)	12 (+1)

Saving Throws Str +10, Dex +8, Int +2
Skills Athletics +10, Perception +7, Survival +12
Damage Resistances acid, fire, necrotic, psychic; bludgeoning, piercing damage from nonmagical attacks
Damage Immunities poison
Condition Immunities charmed, exhaustion, frightened, poisoned, stunned
Senses darkvision 300 ft., passive Perception 17
Languages -, telepathy 50 ft.
Challenge 13 (10,000 XP)

SPECIAL TRAITS

• Blood Frenzy. The arnsenon has advantage on melee attack rolls against any creature that doesn’t have all its hit points.
• Hivemind. The arnsenon’s Intelligence score increases by 1 for each arnsenon within 60 feet.
• Innate Spellcasting. The arnsenon’s innate spellcasting ability is Wisdom (spell save DC 15). The arnsenon can innately cast the following spells, requiring no material components:
  • At will: detect thoughts, hellish rebuke
  • 3/day: pass without trace
  • 1/day: plane shift (self only)
• Magic Resistance. The arnsenon has advantage on saving throws made against spells and other magical effects.
• Unbreathing. The arnsenon does not need to breathe or sleep.

ACTIONS

• Multiattack. The arnsenon attacks twice.
• Bite. Melee Weapon Attack: +10 to hit, reach 5 ft., one target. Hit: 31 (4d12+5) magical piercing damage.
• Tri-Beam. Ranged Weapon Attack: +8 to hit, range 100/400 ft., one target. Hit: 25 (4d10+3) force damage.