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Gulper Behemoth

Gargantuan · Monstrosity · CR 9 · Unaligned

Source. Tome of Beasts 2

16 (natural armor)

188 (13d20+52)

Ability Scores

Core attributes and their modifiers.

STR

DEX

CON

INT

-3

WIS

CHA

-3

Overview

Category Monsters

Size Gargantuan

Type Monstrosity

Alignment Unaligned

XP 5000

Initiative Bonus +0

Movement

Swim 40 ft (12.2 m)

Senses

Blindsight 120 ft (36.6 m)

Passive Perception 10

Resistances & Immunities

Damage Resistances

acid, thunder

Damage Vulnerabilities

piercing

Condition Immunities

blinded

Traits

Death Burst

The gulper behemoth explodes when it drops to 0 hp. Each creature within 40 feet of it must succeed on a DC 16 Constitution saving throw, taking 21 (6d6) acid damage on a failed save.

Echolocation

The gulper behemoth can’t use its blindsight while deafened.

Keen Hearing

The gulper behemoth has advantage on Wisdom (Perception) checks that rely on hearing.

Water Breathing

The gulper behemoth can breathe only underwater.

Actions

Bite

+9 to hit, reach 10 ft (3 m). Hit: 6d10+7 piercing damage.

Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 40 (6d10 + 7) piercing damage. If the target is a creature, it is grappled (escape DC 16). Until this grapple ends, the target is restrained, and the gulper behemoth can't bite another target.

Sonic Pulse

Recharge 5–6

The gulper behemoth expels a sonic pulse in a 60-foot cone. Each creature in that area must make a DC 16 Constitution saving throw. On a failure, the creature takes 21 (6d6) thunder damage and is stunned until the end of its next turn. On a success, the creature takes half the damage and isn't stunned.

Swallow

The gulper behemoth makes one bite attack against a Large or smaller creature it is grappling. If the attack hits, the creature is also swallowed, and the grapple ends. While swallowed, the creature is blinded and restrained, it has total cover against attacks and other effects outside the behemoth, and it takes 14 (4d6) acid damage at the start of each of the behemoth's turns.

If the gulper behemoth takes 20 damage or more on a single turn from a creature inside it, the behemoth must succeed on a DC 15 Constitution saving throw at the end of that turn or regurgitate all swallowed creatures, which fall prone in a space within 10 feet of the behemoth. If the behemoth dies, a swallowed creature is no longer restrained by it and can escape from the corpse by using 15 feet of movement, exiting prone.

About Gulper Behemoth

Gulper Behemoth is a gargantuan monstrosity with a Challenge Rating of 9. It has a unaligned alignment.

In combat, this creature maintains an Armor Class of 16 and possesses 188 hit points (derived from 13d20+52).

GM Tips: Using Gulper Behemoth

1 tips available

When using Gulper Behemoth in your D&D 5e campaign, consider these tactical approaches:

Aquatic Combat: This creature can swim at 40 ft. It has advantage in water environments. Consider fighting on land or using water-based spells against it.

Player Guide: Facing Gulper Behemoth

1 strategies available

When your party encounters this creature, keep these strategies in mind:

Aquatic Combat Defense: This creature can swim at 40 ft! It has advantage in water. Fight on land if possible. Use 'Control Water' or drain water sources to limit its mobility.

Encounter Building Calculator

Standard Party Encounter (4-5 characters):

This creature is a medium encounter for a party of 4 characters of level 9.

Solo Encounter:

A single character of level 12 (up to level 20) can face this creature in a medium to hard encounter.

Experience Point Thresholds:

Medium: 9,000 XP
Hard: 13,500 XP
Deadly: 18,000 XP

Based on D&D 5e Dungeon Master's Guide encounter building guidelines. CR roughly equals party level for medium encounters.

Frequently Asked Questions

What is the challenge rating of Gulper Behemoth?: Gulper Behemoth has a Challenge Rating of 9, making it appropriate for parties of level 9.0.
What type of creature is Gulper Behemoth?: Gulper Behemoth is a Gargantuan Monstrosity, which affects how certain spells and abilities interact with it.