Harbor Drake

Medium dragon, unaligned

Armor Class 15 (natural armor)

Hit Points 84 14d8+28

Speed Swim: 60ft

STR

15 +2

DEX

16 +3

CON

15 +2

INT

7 -2

WIS

12 +1

CHA

10 0

Saving Throws DEX +6

Skills Acrobatics +6, Perception +4. Stealth +6

Damage Immunities poison

Condition Immunities paralyzed, poisoned, prone

Senses darkvision 60 ft., passive Perception 14

Languages Draconic

Challenge 5 (1,800 xp)

Camouflage: The drake has advantage on all Stealth checks while underwater.
Death Throes: If the drake is reduced to 0 hit points, it explodes in a cascade of magical energy. All creatures within 10 ft. of the drake must make a DC 12 DEX saving throw, taking 11 2d10 force damage, or half as much on a success. Creatures of the dragon type are always considered vulnerable to this damage, even if they would otherwise be resistant or immune.
Pack Tactics: The drake has advantage on an attack roll against a creature if at least one of the drake's allies is within 5 ft. of the creature and isn't incapacitated.
Water Breathing: The drake can only breathe underwater.

Actions

Multiattack: The drake makes two bite attacks.
Bite: Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 7 2d4+2 piercing damage, and a creature must make a DC 12 CON saving throw or take an additional 2 1d4 poison damage.