D&D Monster Monday: Underworld Cerberus

D&D Monster Monday Underworld Cerberus

Alerting the underworld cerberus of your position was merely the second dumbest thing you did today. The first was attempting to hide from it. You run for your life, but the howls and growls the three heads gleefully let out sound closer and closer each second.

I’ve been enjoying learning about definitely not Greece Theros as I read through my copy of Mythic Odysseys of Theros that I got for Christmas. It’s a great book and has a ton of fantastic Greek Mythology-inspired creatures for DMs to play around with.

I figured it’s high-time I showcased one of these fantastic creatures. It was a tough choice, but ultimately I went with one of the two cerberi, the underworld cerberus.

While the two-headed cerberus is cool and more of a classic rendition of Cerberus, the three-headed underworld cerberus variant is a nasty foe to run into. They’re powerful, terrifying, and ridiculously fast. They’re the perfect guard dog to ensure that no souls escape from the underworld.

Let’s tread carefully as we learn all about the ever-vigilant watchdogs, the underworld cerberus!

A red, three-headed, dog-looking creature with beady green eyes and sharp teeth
Suffice to say, these creatures look as terrifying as their statblock. Credit: WotC.

Underworld Cerberus Lore

Three-headed cerberi shoulder the brunt of the work in guarding and patrolling the important locations in the Underworld. Treasure, portals, souls of the dead, you name it and the underworld cerberus will guard it with its life. Their tenacity and effectiveness as guards earn successful underworld cerberi lucrative contracts with powerful demons and other such creatures.

However, not every cerberus allies themselves with a powerful demonic overlord. Some simply live their lives hunting down wayward souls in the underworld.

Cerberi also have a thirst for blood. They’re constantly hungry and love the taste of human flesh in particular. It’s not unheard of for evil-hearted creatures to lure a cerberus out of the underworld to attack a nearby town or village.

Underworld Cerberus Stats and Abilities

You can find the underworld cerberus’ statblock on page 215 of Mythic Odysseys of Theros.


Size: Large monstrosity
AC: 16 (natural armor)
HP: 104 (11d10 + 44)
Speed: 60 ft.
STR: 19 (+4)
DEX: 12 (+1)
CON: 18 (+4)
INT: 10 (+0)
WIS: 16 (+3)
CHA: 9 (-1)

What a beefy creature! 16 AC with 104 HP is quite solid before accounting for the pair of damage immunities the underworld cerberus has.

Their stat array is respectable. Their Strength and Constitution are amazing which is important for a melee brute-type creature like the cerberus. However, that mediocre Dexterity is a potential issue.

Regardless, even with a measly +1 to Dexterity saves, the cerberus still has above-average common saving throw abilities thanks to their high Wisdom and Constitution.

I was taken aback when I first read the underworld cerberus’ speed. 60 ft. of movement for such an enormous creature is buck wild! I actually googled it to make sure it wasn’t a misprint after seeing that they also have Aggressive. This is a lightning-fast brute that truly does not give two shits if you can initially outrange it.

Resistances, Immunities, Saves, and Skills

Skills: Athletics +7, Perception, +9, Stealth +4
Damage Immunities: fire, necrotic
Condition Immunities: blinded, charmed, deafened, exhaustion, frightened, stunned
Senses: truesight 30ft., passive Perception 19
Languages: understands all languages but can’t speak
CR: 6 (2,300 XP)

The underworld cerberus has a few useful skill proficiencies, all of which focus on their combat or guard proficiency. Good luck shoving or grappling this beast with their +7 to Athletics checks.

Best of luck sneaking past that 19 Passive Perception or their +9 to Perception checks too. Oh, plus their 30 ft. of truesight should you have the bright idea to use invisibility to attempt to bamboozle them. Face it, if an underworld cerberus is in your way either you’re dying or they are. There’s no avoiding these guard dogs!

Both their damage immunities are super valuable. There are a plethora of fire spells that PCs sling at their foes throughout the entirety of the game. Plus, necrotic damage also starts to shine in the mid to late game due to powerful spells using that damage type as well.

Their saving throw abilities are all-around decent, but they certainly look even better when coupled with the six condition immunities they have. They’re not an easy creature to slow down by any means!

CR 6 feels low for this creature. 120 ft. of movement a turn, amazing action economy, pack tactics, and beefy defenses make the underworld cerberus an absolute monster in combat. They feel absolutely loaded with strong mechanics and enhancements that as-is I think they could easily hit CR 7 or 8 and still be respectable foes.

Traits and Abilities

Aggressive. As a bonus action, the cerberus can move up to its speed toward a hostile creature that it can see.

Multiheaded. The cerberus can’t be surprised, and it has advantage on saving throws against being knocked unconscious.

Pack Tactics. The cerberus has advantage on an attack roll against a creature if at least one of the cerberus’ allies is within 5 feet of the creature and the ally isn’t incapacitated.

Aggressive is basically a free bonus action Dash. Which gives them a total of 120 ft. of movement per turn. Realistically, I can’t think of many situations where the underworld cerberus will want to use a Dash action to move away from their prey. Their sole duty is to guard whatever it is they’re guarding.

They’ll keep moving forward to the enemy until either they or their prey is dead.

Multiheaded is a nice insurance trait for the rare instance that the party somehow gets the jump on an underworld cerberus. Plus, it gives them advantage against yet another condition making them even harder to crowd control.

Pack Tactics feels nasty. They have a +7 to hit with their three-attack Multiattack already. Tossing advantage on top of that almost feels unfair. Almost…


Multiattack. The cerberus makes three bite attacks.

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) piercing damage plus 3 (1d6) fire damage.

Breath Weapon (Recharge 5-6). The cerberus exhales a 30-foot cone of molten rock. Each creature in the cone must make a DC 15 Dexterity saving throw, taking 21 (6d6) fire damage on a failed save, or half as much on a successful one. On a failed save, a creature is also restrained by the hardening rock. A creature can make a DC 15 Strength (Athletics) check as an action, freeing itself or a creature within reach from the rock on a success. The rock has AC 17 and 20 hit points, and is immune to fire, poison and psychic damage.

Both of the underworld cerberus’ attack options are phenomenal.

The first is the three-Bite Multiattack which boasts an enormous amount of action economy and a total of 42 damage split between piercing and fire damage. It’s quite accurate to boot with a +7 to hit on each attack.

Their rechargeable Breath Weapon attack is a fantastic mid-ranged AoE option. It’s a 30 ft. cone that deals an average of 21 damage per person, provided that they fail the save. Not only that, but any creature hit by the full force of the breath weapon is restrained, giving any follow-up attacks made by the cerberus or their allies advantage if the target doesn’t free themselves in time.

Oh, and it recharges 33% of the time making it a solid ability to spam whenever you can clip at least two enemies with it.

Underworld Cerberus Strengths

Jaws of Steel

Making three Bite attacks or clipping two enemies with Breath Weapon nets the cerberus an average of 42 damage per turn. This alone gives them a ton of offensive power, but they’ve got a few extra goodies on top of all this.

Specifically speaking, they have a couple of reliable ways to gain advantage with their Bite attacks. Pack Tactics is the easiest method of doing so as it merely requires a second creature to stand next to the cerberus’ target.

However, Breath Weapon has the potential to root and restrain a few targets that are caught up in it. Restrained targets have disadvantage on Dexterity saving throws and are attacked at advantage giving both Breath Weapon and Bite increased potency against targets stuck in the hardening rock.

prince zagreus petting his three-headed red cerberus after yet another death in the underworld
The only mark against the underworld cerberus is that they’ll never be as cute as Cerberus from Hades. Credit: Supergiant Games.

High-Powered Action Economy

The underworld cerberus’ offenses alone earn this label. A three attack Multiattack and a wide-spread 30 ft. cone of fire with a restraining mechanic is a truckload of action economy.

Yet that’s not considering their unbelievable movement. Hell, their baseline movement of 60 ft. is double that of a medium-sized adventurer. They basically get a Dash action for free.

However, they also have Aggressive which lets them take a bonus action to move up to their speed toward a hostile creature. Considering that they have no other uses for a bonus action, there’s almost no reason to not take this free Dash action every turn it’s available.

Beefy Defenses

The underworld cerberus is no glass cannon. These are beefy boys. Their 16 AC and 104 HP is a solid baseline that is further bolstered by two solid damage immunities.

Aside from Dexterity, they have a solid set of common saving throw abilities. Plus, Dexterity is at least a +1 so it’s not terrible it’s just mediocre.

Last but not least, they have a smattering of condition immunities plus Multiheaded which gives them immunity to being surprised and advantage against the Unconscious condition.

They’re fast, powerful, and damn-near unstoppable!

Underworld Cerberus Weaknesses

I didn’t expect to have back-to-back Monster Monday articles where I struggled to find a noticeable flaw, but here we are.

Long-ranged attacks are maybe the one weakness of the underworld cerberus, especially if they can target the creature’s weak Dexterity modifier. However, I struggle to find a scenario where ranged units can constantly outpace a creature that can move 120 ft. per turn without taking the Dash action.

Seriously, Aggressive feels like overkill on a creature with 60 ft. of speed per turn. Your only options are to find some way to crowd control the cerberus and pray that you can nuke it before it’s able to sink its teeth into the party’s wizard.

How to Play an Underworld Cerberus

Let’s Play Some Fetch!

Dogs love to play fetch. Well, at least mine does. Regardless of their demonic, terrifying, monstrous appearance, the underworld cerberus is just a big puppy!

The goal here is to find long-ranged attackers like magic-users or archers and rush to them with our 120 ft. of movement thanks to Aggressive. When we get there, chomp down on those squishy enemies with our three-attack Multiattack and rip them to shreds.

If they’ve mispositioned themselves, it could take a couple of turns for their tanky frontline to make it over to them to help pry the cerberus off of them.

Pick On the Stragglers

This is similar to the previous tactic, but with one caveat. We gun for any enemy that’s out of position, regardless of their potential AC.

By rushing to an out-of-position target, we’re utilizing one of the underworld cerberus’ greatest strengths, their movement. Clocking in at 2-4 times the speed of an average adventurer means that you probably have your pick of targets on the battlefield.

Ergo, if you see a target that’s 60+ ft. away from their allies you can potentially decimate them for a round or two before their allies can close the gap and provide aid.

This not only makes things dangerous for the target, but it also forces the party’s melee attackers to waste their actions dashing instead of dealing damage. This in turn bolsters the cerberus’ survivability since they have fewer attacks to deal with during these rounds.

Once the party is in position, either finish your target or choose another out-of-position target to chase after and restart this game of cat and mouse.

5 Underworld Cerberus Plot Hooks

  1. The Bloodthirsty Pack – A rogue underworld cerberus has crossed over to the mortal realm and is leading a pack of two-headed cerberi on a rampage across the countryside. Villages and towns have been decimated by this ravaneous pack.
  2. Well-Guarded Secrets – Many treasures and secrets lay deep in the Underworld. Unfortunately, they’re well-hidden. However, rumor has it that if you see a underworld cerberus on guard, there’s a good chance they’re guarding something worthy of stealing.
  3. Saving a Friend – Your fallen comrade wasn’t able to be resurrected. Their soul was intercepted by… something. You might have some success if you can fish them out of the Tartyx yourself, provided whatever intercepted them doesn’t slaughter you first.
  4. Severing an Alliance – You’ve slain a powerful demon lord in the Underworld. However, now the pack of underworld cerberi they controlled are running rampant. Order must be restored for the good of the Underworld.
  5. Foolish Mages – A group of wizards sought to summon an underworld cerberus to use as a guard dog for their lair. Unfortunately, the cerberus thought they were food. Dispose of it before it leaves the lair and decimates the fauna of the nearby forest.


All in all, the underworld cerberus is a terrifying beast. Sure, they don’t have long-ranged attacks or anything like that, but when you have ungodly movement speed and a giant-ass conal Breath Weapon who needs them?

These dogs are hungry for blood, damn fast, and unbelievably powerful both defensively and offensively. There’s very little that will slow them down and you sure as hell can’t rely on sneaking past them. They are, in fact, the ultimate guard dog.

I won’t say that they’re some fresh take on a classic mythological creature or anything. Yet, they don’t need to be. WotC hit the nail on the head and made a terrifying Underworld guard dog that will surely get the job done.

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