Demon Lord, Tsathogga, The Frog God

Gargantuan fiend (demon), chaotic evil

Armor Class 20 (natural armor)
Hit Points 546 (28d20 + 252)
Speed 40 ft., swim 20 ft.

29 (+9) 15 (+2) 28 (+9) 19 (+4) 18 (+4) 23 (+6)

Saving Throws Dexterity +12, Constitution +19, Wisdom +14, Charisma +16
Skills Arcana +14, Insight +14, Perception +24, Survival +14
Damage Resistances cold, fire
Damage Immunities acid, lightning, poison; bludgeoning, piercing, and slashing from nonmagical weapons
Condition Immunities charmed, exhaustion, frightened, paralyzed, poisoned
Senses truesight 120 ft., passive Perception 34
Languages Aquan, Abyssal, Common, Giant, Infernal, Terran, telepathy 120 ft.
Challenge 35 (330,000 XP)

Special Traits


  • 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.


This massive creature appears to be a gigantic frog no less than 60 feet long. Its body is covered with warts and sores, and each oozes putrid, yellowish mucus. Its eyes are red and glow with an inherent evil. The creature’s massive mouth sports rows of sharpened teeth, each at least as long as a sword. This foul frog-demon cares less about the machinations of men and power than he does about obliterating light and life with the slow oozing sickness and decay that he represents. He is the viscous dark evil bubbling up from beneath the surface, the foul corruption at the heart of the earth.

Tsathogga makes his home on both Tarterus and the Abyss, spending equal amounts of time in both places. His lair is a vast swamp of filth deposited by the River Styx as it flows between the two planes.

Tsathogga’s main form is of a colossally bloated humanoid frog with spindly, elongated limbs and fingers. His corpulent body exudes all manner of foul oils and fluids, which leak into the vile swamp in which he lies. He has positioned himself so that all of the slime and filth from the River Styx feeds into his gaping, toothy maw. He rarely moves and rarely speaks other than to emit an unintelligible shrieking. Tsathogga thoughtlessly commands a host of evil creatures, notably his own vile frog race, the tsathar.

Tsathogga is 60 feet long and 40 feet tall. He weighs about 200 tons.

Tsathogga prefers to avoid direct combat simply because he usually has better things to do than waste time killing the latest group of would-be demon killers. If threatened or attacked, he usually summons his minions to battle his opponents. If Tsathogga does enter combat, he almost always begins by striking the nearest opponent with his tongue, pulling that foe in and swallowing him. If he is near the muck and filth that permeates his home plane, he likes to dive or bury himself underneath it so if a swallowed opponent does manage to cut his way out of Tsathogga’s gullet, he usually drowns or suffocates before he sees daylight again.

Servants of Tsathogga

Followers of Tsathogga are the tsathar and some few evil and vile humans or giants. He has few other worshippers, though it is rumored that an evil cult of sahuagin worships him on the Material Plane. Devout followers of Tsathogga are called Lords of the Gaping Maw and must sign a pact of evil with Tsathogga.

Section 15: Copyright Notice

Tome of Horrors © 2018, Frog God Games, LLC; Authors: Kevin Baase, Erica Balsley, John “Pexx” Barnhouse, Christopher Bishop, Casey Christofferson, Jim Collura, Andrea Costantini, Jayson ‘Rocky’ Gardner, Zach Glazar, Meghan Greene, Scott Greene, Lance Hawvermale, Travis Hawvermale, Ian S. Johnston, Bill Kenower, Patrick Lawinger, Rhiannon Louve, Ian McGarty, Edwin Nagy, James Patterson, Nathan Paul, Patrick N. Pilgrim, Clark Peterson, Anthony Pryor, Greg Ragland, Robert Schwalb, G. Scott Swift, Greg A. Vaughan, and Bill Webb