Merrow

5e compatible shield

Large monstrosity, chaotic evil

Armor Class 13 (natural armor)
Hit Points 45 (6d10 + 12)
Speed 10 ft., swim 40 ft.

STR DEX CON INT WIS CHA
18 (+4) 10 (+0) 15 (+2) 8 (-1) 10 (+0) 9 (-1)

Saving Throws 
Skills 
Damage Resistances 
Damage Immunities 
Condition Immunities 
Senses darkvision 60 ft., passive Perception 10
Languages Abyssal, Aquan
Challenge 2 (450 XP)

Amphibious. The merrow can breathe air and water.

Actions

Multiattack. The merrow makes two attacks: one with its bite and one with its claws or harpoon.

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) piercing damage.

Claws. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 9 (2d4 + 4) slashing damage.

Harpoon. Melee or Ranged Weapon Attack: +6 to hit, reach 5 ft. or range 20/60 ft., one target. Hit: 11 (2d6 + 3) piercing damage. If the target is a Huge or smaller creature, it must succeed on a Strength contest against the merrow or be pulled up to 20 feet toward the merrow.