Merregon

AC: 16

Initiative: +2 (12)

HP: 45 (6d8 + 18)

Speed: 30 ft.

Resistances: cold; bludgeoning, piercing, slashing from nonmagical attacks that aren't silvered

Immunities: fire; poison

Condition Immunities: frightened; poisoned

Senses: darkvision 60 ft., Passive Perception 11

Languages: understands Infernal but can't speak, telepathy 120 ft.

CR: 4 (XP 1,100; PB +2)

Devil's Sight.

Magical darkness doesn't impede the merregon's darkvision.

Magic Resistance.

The merregon has advantage on saving throws against spells and other magical effects.

Actions

Multiattack.

The merregon makes three Halberd attacks.

Halberd.

Melee Weapon Attack: +6 to hit, reach 10 ft., one target. Hit: 9 (1d10 + 4) slashing damage.

Heavy Crossbow.

Ranged Weapon Attack: +4 to hit, range 100/400 ft., one target. Hit: 7 (1d10 + 2) piercing damage.

Loyal Bodyguard.

When another Fiend within 5 feet of the merregon is hit by an attack roll, the merregon causes itself to be hit instead.