Armor Class 13
Hit Points 40 (9d8)
Speed 30 ft., swim 40 ft.
Saving Throws DEX +5, INT +5
Skills History +5, Nature +5, Perception +4, Survival +4
Damage Resistances cold, fire, lightning, [object Object]
Damage Immunities acid, poison
Condition Immunities poisoned
Senses blindsight 60 ft., darkvision 60 ft., passive Perception 14
Languages Abyssal, Infernal, telepathy 60 ft.
Challenge 3
Magic Resistance. The merrenoloth has advantage on saving throws against spells and other magical effects.
Magic Weapons. The merrenoloth's weapon attacks are magical.
Teleport. As a bonus action, the merrenoloth magically teleports, along with any equipment it is wearing or carrying, up to 60 feet to an unoccupied space it can see.
Multiattack. The merrenoloth uses Fear Gaze once and makes one oar attack.
Oar. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 8 (2d4 + 3) slashing damage.
Fear Gaze. The merrenoloth targets one creature it can see within 60 feet of it. The target must succeed on a DC 13 Wisdom saving throw or become frightened for 1 minute. The frightened target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
Mordenkainen's Tome of Foes, p. 250