Acidic Hide. A creature that touches Tsathogga or hits it with a melee attack while within 10 feet of it takes 35 (10d6) acid damage. Any nonmagical weapon made of metal or wood that hits Tsathogga instantly dissolves before dealing damage.

Amphibious. Tsathogga can breathe both water and air.

Innate Spellcasting. Tsathogga’s innate spellcasting ability is Charisma (spell save DC 24, +16 to hit with spell attacks).

• At will: acid arrow (5th level), bane, blindness/deafness, blight, command, detect magic, fog cloud, grease, inflict wounds (5th level)

• 7/day each: antilife shell, circle of death, cloudkill, contagion, counterspell, dispel magic, dominate beast, dominate person, earthquake

• 3/day each: geas, harm

• 1/day each: control weather, power word kill, storm of vengeance, wish

Legendary Resistance (3/day). If Tsathogga fails a saving throw, it can choose to succeed instead.

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

Magic Weapons. Tsathogga’s weapon attacks are magical.

Unholy Aura. An unholy aura surrounds Tsathogga out to a radius of 40 feet. A creature who enters or begins their turn in the area must make a DC 20 Wisdom saving throw. On a failed saving throw, the target is frightened for 1 minute. While frightened, they are paralyzed. A frightened target can repeat the saving throw at the end of each of its turns, ending the effect on a success.

Actions

Multiattack. Tsathogga uses its Blasphemous Croak ability, then uses its tongue attack. If there is a creature within range, it can then use its bite attack and two claw attacks.

Bite. Up to three targets of Huge size or smaller within 10 feet of Tsathogga must make a DC 27 Dexterity saving throw. On a successful saving throw, it takes 44 (10d6 + 9) piercing damage, plus 35 (10d6) acid damage, and is grappled. On a failed saving throw, the target is swallowed. While swallowed, the creature is blinded and restrained, it has total cover against attacks and other effects outside of Tsathogga, and it takes 56 (16d6) acid damage at the start of each of Tsathogga’s turns. If Tsathogga takes 50 damage or more on a single turn from a creature inside it, Tsathogga must succeed on a DC 25 Constitution saving throw at the end of that turn or regurgitate all swallowed creatures, which fall prone in a space with 10 feet of Tsathogga. If Tsathogga dies, a swallowed creature is no longer restrained by it and can escape from the corpse using all of its movement, exiting prone.

Claw. Melee Weapon Attack: +19 to hit, reach 10 ft., one target. Hit: 40 (9d6 + 9) slashing damage plus 35 (10d6) acid damage.

Tongue. Tsathogga chooses one creature that it can see within 40 feet of it. That target must make a DC 28 Dexterity saving throw. On a failed saving throw, the target takes 37 (8d6 + 9) bludgeoning damage plus 35 (10d6) acid damage and is grappled. Tsathogga can use a bonus action to pull a creature grappled by it up to 40 feet towards it.

Blasphemous Croak. Tsathogga utters a blasphemous croak audible to all creatures within 300 feet of it. Those that can hear it must make a DC 24 Wisdom saving throw. On a failed saving throw, the target takes 28 (8d6) necrotic damage and 28 (8d6) thunder damage and is stunned for 1 minute. On a successful saving throw, the target takes half damage and is not stunned. A stunned creature can repeat the saving throw at the end of each of its turns, ending the effect on a success.

Summon (1/day). Tsathogga summons 2d6 hezrous, 2d4 greruors, 1 nalfeshnee, or 1 balor. The summoned demon appears in an unoccupied space within 60 feet of Tsathogga, and can’t summon other demons. It remains for 1 minute, until it or Tsathogga is slain, or until Tsathogga takes an action to dismiss it.

Legendary Actions

Tsathogga can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. Tsathogga regains spent legendary actions at the start of its turn.

Retract Tongue. Tsathogga can pull one creature grappled by its tongue attack 40 feet towards it.

Quake. Tsathogga causes the area around it to violently shake in a radius of 100 feet. Creatures in the area must make a DC 24 Dexterity saving throw or fall prone. Until the beginning of Tsathogga’s next turn, the ground continues shaking, and creatures must repeat the saving throw to rise from prone.

Seeping Darkness (Costs 2 Actions). Magical darkness fills the area surrounding Tsathogga out to a distance of 50 feet. The darkness spreads around corners, douses any nonmagical lights, and any light-producing spell of 6th level or lower is immediately dispelled. The magical darkness remains for 1 hour, or until Tsathogga uses an action to dismiss it.

Lair Actions

On initiative count 20 (losing initiative ties), Tsathogga takes a lair action to cause one of the following magical effects.

Acid Swamp. Tsathogga chooses an area of swamp that it can see within 120 feet of it. The area can be no larger than a 30-foot cube. Creatures in the area must make a DC 24 Strength saving throw. On a failed saving throw, the target takes 21 (6d6) acid damage and is grappled (escape DC 24). On a successful saving throw, the target takes half damage and is not grappled. On the next initiative count 20, the target takes an additional 21 (6d6) acid damage if it is still grappled by this lair action.

Insect Swarms. Tsathogga causes 7 (2d6) insect swarms to converge on an area of Tsathogga’s choosing that it can see.

Swamp Mist. Tsathogga causes swamp mist to rise. This acts as if Tsathogga had cast the fog cloud spell as a 9th level spell. Tsathogga does not need to maintain concentration on this effect.

gargantuan

fiend

cr35

tome-of-horrors

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