Large Fiend, lawful evil
Armor Class 17 (natural armor)
Hit Points 195 (26d10+52)
Speed fly +40, swim +120, walk +30
Challenge 12
Saving Throws con +6, str +7, wis +5
Skills perception +1
Damage Resistances cold; nonmagical B/P/S attacks
Damage Immunities fire, lightning, poison
Condition Immunities poisoned
Senses darkvision 120', passive Perception 11
Languages Infernal, telepathy 120'
Devil's Sight. Magic darkness doesn't impede its darkvision.
Influence Weather. Nearby weather responds to devil's desires. At start of each min devil can choose to change precipitation and wind within 1 mile of it by one stage up or down (no action required). This works like the changing weather conditions aspect of the control weather spell except devil can't change temperature and conditions change immediately.
Magic Resistance. Advantage: spell/magic effect saves.
Multiattack. Three Claws attacks and one Tempest Trident attack or it makes three Lightning Ray attacks.
Claws. Melee Weapon Attack: +7 to hit, 5 ft., one target, 10 (2d6+3) slashing damage.
Tempest Trident. Melee Weapon Attack: +7 to hit, 5 ft., one target, 16 (2d12+3) piercing damage + 7 (2d6) cold. A creature hit by this: knocked prone (DC 16 Str negates) by a gust of wind channeled through the trident.
Lightning Ray. Ranged Spell Attack: +8 to hit, 150 ft., one target, 18 (4d8) lightning.
Crown of Water (1/Day). The water on devil's head erupts in a geyser. Each creature within 10 ft. of devil: 35 (10d6) cold (DC 16 Con half). For 1 min when a creature enters a space within 10 ft. of the devil for 1st time on a turn or starts its turn there that creature: DC 16 Con save or take 10 (3d6) cold.
Source: Tome of Beasts 3 · OGL/Open