Hydroloth

Medium fiend (yugoloth), neutral evil

Armor Class

15

Hit Points

135 (18d8 + 54)

Speed

20 ft., swim 40 ft.

STR

12 (+1)

DEX

21 (+5)

CON

16 (+3)

INT

19 (+4)

WIS

10 (0)

CHA

14 (+2)

Damage Immunities

acid, poison

Damage Resistances

cold, lightning; bludgeoning, piercing, and slashing from nonmagical attacks

Condition Immunities

poisoned

Senses

blindsight 60 ft., darkvision 60 ft., passive Perception 14

Skills

Insight +4, Perception +4

Languages

Abyssal, Infernal, telepathy 60 ft.

Challenge

9 (5,000 XP)

Amphibious. The hydroloth can breathe air and water.

Innate Spellcasting. The hydroloth’s innate spellcasting ability is Intelligence (spell save DC 16). It can innately cast the following spells, requiring no material components:

  • At will: darkness, detect magic, dispel magic, invisibility (self only), water walk

  • 3/day each: control water, crown of madness, fear, phantasmal killer, suggestion

Magic Resistance. The hydroloth has advantage on saving throws against spells and other magical effects.

Magic Weapons. The hydroloth’s weapon attacks are magical.

Secure Memory. The hydroloth is immune to the waters of the River Styx as well as any effect that would steal or modify its memories or detect or read its thoughts.

Watery Advantage. While submerged in liquid, the hydroloth has advantage on attack rolls.

Actions

Multiattack The hydroloth makes two melee attacks. In place of one of these attacks, it can cast one spell that takes 1 action to cast.

Claws Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 14 (2d8 + 5) slashing damage.

Bite Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 16 (2d10 + 5) piercing damage.

Steal Memory (1/Day) The hydroloth targets one creature it can see within 60 feet of it. The target takes 4d6 psychic damage, and it must make a DC 16 Intelligence saving throw. On a successful save, the target becomes immune to this hydroloth’s Steal Memory for 24 hours. On a failed save, the target loses all proficiencies, it can’t cast spells, it can’t understand language, and if its Intelligence and Charisma scores are higher than 5, they become 5. Each time the target finishes a long rest, it can repeat the saving throw, ending the effect on itself on a success. A greater restoration or remove curse spell cast on the target ends this effect early.

Teleport The hydroloth magically teleports, along with any equipment it is wearing or carrying, up to 60 feet to an unoccupied space it can see.

medium
fiend
cr9
mordenkainens-tome-of-foes
(p. 249)