Powerful Monster Combos

[Asisreo1]

I'd like to open a discussion about your favorite Monster Combinations, whether they were famous or infamous at your table. We can also discuss things that aren't specifically monster-to-monster combos like Monster-and-Terrain stuff and Monster-and-Trap.

Anything that makes the fight more interesting overall.

Here's some examples:

Banshee and 1d4 Will o' Wisps. The Will o' Wisps are dangerous because they can instantly kill and heal HP from enemies who are at 0 HP, and the Banshee just so happens to have an ability that can drop characters to 0 HP on a failed save. The same could be done with a demilich but Banshees are closer to CR and more likely to appear in a campaign.

Bone Naga and Medusa. The Bone Naga has an interesting spell called Bestow Curse. Able to fling it out without much hesitation, it can inflict disadvantage to a saving throw of its choice. A saving throw like Constitution, which is important to resist the Medusa's petrifying gaze. Also, a failure by 5 or more (under 9) instantly petrifies. Even a +4 to con saves will have you struggling not to instantly get petrified, which casually leads you into a position where you have a harder time attacking the medusa. Dynamic stuff indeed.

Bullywugs, Crocodiles, and Lily Pads. Bullywugs have the ability to leap across 20ft gaps. This means having situations where the combat starts in an area with lily pads or rocks spread 10-20ft apart in a crocodile-infested swamp lake causes the players to think strategically about how they have to position themselves. They can attempt to swim from one lily pad to another but they risk passing some crocodile's opportunity attack while they're being stealthy underwater. They can attempt to leap, but you'd need a 20 Strength score to safely leap from the minimum distance, unless they have a jump modifying feature like Barbarians or Monks. They can of course teleport but that could get expensive and inefficient.

Merrow and Rough Waters. If a Merrow hits a PC who isn't particularly strong, they can use their harpoon to pull them into rough waters and bite/impale them while the PC struggles to return to the surface with difficult checks.

Cloaker and Roper. The Roper has Tendrils which not only grapple/restrains but also gives disadvantage to strength checks and saves. This makes it hard for the victim to get out of the tendrils and the cloaker's attachment. Add on a creature that knocks prone on Strength Saves and you've got a vicious cycle. Prone->Tendrils->Cloak. Cloak->Tendrils->Prone. Tendrils->Cloak->Prone. Etc. If you add onto it an invisible environment and both creatures in stealth, and you've got yourself a decent low-mid-tier level encounter.

Any other thoughts about my combinations or new combinations that you've come up with?

[Tvtyrant]

Storm Giant on a Roc. The giant summons a storm before the fight if possible, then strafes the party with lightning bolts and rocks. The roc flies the storm giant away from the party and keeps the giant out of arms reach, while they can't shoot back due to the winds.

[MaxWilson]

Star Spawn Mangler with any other Star Spawn except Seer--Hulk/Larval Mage/Grue all have ways to grant it advantage (poisoning, stunning, restraining) so it can activate its psychic damage buzz saw. And Seers go well together with Hulks for the psychic mirror combo (target someone next to the Hulk with Collapse Distance to double the damage, or triple with two Hulks).

[No brains]

An Azer Riding a Frost Salamander
For a few points of fire damage a round from the Azer's heated body, the Frost Salamander can spam its Frost Breath every round.

[loki_ragnarock]

Banshee and 1d4 Will o' Wisps. The Will o' Wisps are dangerous because they can instantly kill and heal HP from enemies who are at 0 HP, and the Banshee just so happens to have an ability that can drop characters to 0 HP on a failed save. The same could be done with a demilich but Banshees are closer to CR and more likely to appear in a campaign.



A substitute for the Banshee is the Catoblepas, which trades the wide effect for a narrower, higher DC instant 0 ability. CR 5. Volo's p129
This is what I get from going from memory. Bodak is the substitute I was thinking of; both have a death gaze, just a different set of mechanics. CR 6 Volo's p127

EDIT

If you can figure out a thematic reason to pair them A Gauth and a Beholder can be something else together.

The Gauth has an ongoing chance to stun, which causes automatic dex save failures.
The Beholder's eye rays are almost all dex saves.

Admittedly this is a higher level fight, but it's sort of a mean spirited one. Substitute the Gauth for a Deep Scion, a Catoblepas (which does have a high DC stun effect, dang it), or anything else that can throw out a stun effect, have angry players.

[CTurbo]

An adult/ancient Black Dragon and a handful of Clay Golems.

The clay golems fight in melee while the black dragon kites from above. It's acid breath weapon heals the golems as they fight.



A Necromancer Wizard and Oathbreaker would be quite the pair. Anything raised by the wizard would get to add proficiency bonus and the Pally's Cha bonus to damage. Even lowly skeletons would hit hard when fighting near the Oathbreaker.

[Catullus64]

One of my favorite monsters for fighting in a trapped environment is the Umber Hulk. Its Confusing Gaze has a chance to send players running into the traps. Roper, of equivalent CR, can also yank people into trapped areas.

[strangebloke]

Pretty much anything where one creature is healed by a form of damage the other deals. Shambling Mound and a bunch of willowisps is my favorite take on that. The Wisps are (sorta) low damage but very hard to kill, the shambling mound is high damage but easy to kill... and the wisps keep healing it. Wisps also make the combat hella lethal.

Another classic is yetis and hobgoblins. Yetis paralyze their enemies and hobgoblins deal insane damage even at range but have low accuracy.

ANOTHER classic is guards and a hobgoblin devastator. The Guards swarm the PCs and dodge while the devastator hides behind cover, popping out to unleash careful fireballs and shatter spells.

[Sorinth]

In terms of terrain
Ghost + high altitude: Just possesses and jump
Merrow and fast flowing river: Pull PCs into the river which drags them far away
Shadow + arrow traps: Shadows can move in/out of the arrow slits where they regroup to hide before attacking again

For creature combos
Lamia + any creature with powerful wisdom saving throw based ability such as Harpy
Anything that can cause the Poisoned condition and Grapple based monsters

[verbatim]

Star Spawn Mangler with any other Star Spawn except Seer--Hulk/Larval Mage/Grue all have ways to grant it advantage (poisoning, stunning, restraining) so it can activate its psychic damage buzz saw. And Seers go well together with Hulks for the psychic mirror combo (target someone next to the Hulk with Collapse Distance to double the damage, or triple with two Hulks).

In my experience the Star Spawn are among the strongest series of official 5e monsters relative to their suggested challenge rating. I'm curious how the new Star Spawn being introduced in the Ravenloft book will turn out.


Other particularly mean/thematic combos:


a Mind Flayer Arcanist who has upcast Invisibility on himself (Mind Blast is not an attack or spell and thus does not drop Invisibility) and several Intellect Devourers.
an Archdruid who has precast Foresight on themselves and Hero's Feast and Animal Shapes on their woodland friends.
a dragon whose lair contains a golem that heals off of their breath weapon.
All 13 Nagpa.

[loki_ragnarock]

I feel like I have to make up for my Catoblepas faux pas by actually putting it in a combo.

So the Catoblepas (CR 5, Volo's p129) death ray has enormous potential to murder the heck out of low con save, low level PCs. It's tail slap has a stun ability, targeting constitution. It's got an aura applying the poisoned condition targeting - you guessed it - constitution. It's DCs are also kind of absurdly high for the CR ascribed; 16 for a CR 5. It really sucks to not be proficient in con saves around this beast. With a failed save against the death ray, a 5th level wizard with average hit points and a 16 con score would go from full hp to zero - and thus dead - with one action. That's effing scary. It also hits like a truck for it's CR, beyond an ability that can straight geek the mage.

Now add in a Babau (CR 4, Volo's p136). A relatively low CR demon with an ace up it's sleeve; at will Heat Metal. That's right; anybody in the party with heavy or medium armor is stuck with disadvantage on attacks for the duration. Break it's concentration, and it can just start it again next action. Add in that it can spam weakening gaze, and there's the potential to bestow disadvantage on attacks *and* half damage on the ones that hit. Oh... and it has a 40ft move speed, so it can probably stay out of melee range after geeking your beefcake. EDIT: Forgot to mention it's also immune to the poison condition, which is easy for the Catoblepas to impart by it's mere presence.

Given that characters with proficiency with con saves are also often characters in heavy or medium armor, you've just divided and potentially conquered a four man party. This one comes online pretty early: this maths out as a hard encounter for a 5th level party of 4.

In short: The mage probably outright dies from a death ray, the fighter is rendered less than useful, and that's round one. After that, the Catoblepas hits like a truck and likely denies PCs their turns via stunning tail, the Babau attempts to stay out of melee range with it's superior mobility or nails remaining stunned opponents with advantage. After about three rounds, the Catoblepas will have recharged it's death ray, and now the party has been softened up; the next person it targets could very well be snuffed.
But with half of the party effectively mitigated in the first round, the odds of a TPK are a little higher than the average.

EDIT
Also, the death ray can straight kill a cleric with average hp and a 14 con, in case anyone's mad about just targeting the mage. I just think snuffing the mage to have the cleric discover that zero hp actually means dead on his turn when he tries to drop a healing word kinda adds to the WTF nature of this whole encounter.

[Kol Korran]

...

So the Catoblepas (CR 5, Volo's p129) death ray has enormous potential to murder the heck out of low con save, low level PCs. It's tail slap has a stun ability, targeting constitution. It's got an aura applying the poisoned condition targeting - you guessed it - constitution. It's DCs are also kind of absurdly high for the CR ascribed; 16 for a CR 5. It really sucks to not be proficient in con saves around this beast. With a failed save against the death ray, a 5th level wizard with average hit points and a 16 con score would go from full hp to zero - and thus dead - with one action. That's effing scary. It also hits like a truck for it's CR, beyond an ability that can straight geek the mage.

I am a relative newcomer to 5e, but I wanted to commemt on the Catoblapes. I motly played 3.5e and PF, but In my teens I played AD&D 2nd ed, and from what you described, from what I them read, and from my (albeit very new and partial) understanding that 5e tries to "get back/ get the feel" of some of the earlier editions of D&D, (minus lethality and other complocations) I'd hazzard a guess that the Catoblapes is a remant/ call back to the AD&D version.

There too, it looked like a simple, even pathetic looking beast, but was an absolute murder. It's death gaze in that addition? Absurd range, and... immediate death, no save. And the stunning tail hit HARD. I have no idea why they made it like that then, and why it is so lethal still, but it sounds awfully close to it, while many other powerfule creatures have been greatly weakened.

I put one of those as a sort of a random encounterz back in those days, without fully looking into all of the details. (I used to photo-copy) the main stats from theMM compendium then). The party met it. Hald died fast, the rest ran. They left the entire area, and to this day one of my players speaks of the unfathomable death beast that is the Catoblapes.

[MaxWilson]

There too, it looked like a simple, even pathetic looking beast, but was an absolute murder. It's death gaze in that addition? Absurd range, and... immediate death, no save. And the stunning tail hit HARD. I have no idea why they made it like that then, and why it is so lethal still, but it sounds awfully close to it, while many other powerfule creatures have been greatly weakened.

For the sake of those who never played AD&D, here's the rules text:


In combat, the catoblepas relies on two forms of attack.

First, it will use its strong, snaky tail to strike and stun its foes. Anyone struck by the tail suffers 1-6 points of damage and has a base 75% of being stunned for 1-10 melee rounds. The base chance of being stunned is lowered by 5% for every level above first, or for each additional Hit Die in the case of monsters and animals.

Despite the danger of a tail strike, the catoblepas' second mode of attack is by far the more fearsome of the two. The gaze of the catoblepas emanates a deathray, with a 60 yard range. Any creature meeting its gaze dies without a saving throw. If the party is surprised by a catoblepas, there is a 1 in 6 chance that someone in the group has met the creature's gaze. Those who close their eyes or act with their eyes averted can still be affected by the deathray, but a saving throw vs. death magic is allowed.

Since the neck of the creature is very weak, it has only a 25% chance of raising its head and using the deathray on subsequent rounds. If the catoblepas and its target are both relatively still, this increases by 15% per melee round. If the catoblepas is forced to follow quick motions it has only a 10% chance of raising its head.

So, it is very much a gimmick monster designed to force the PCs into counterplay (moving around while dodging the tail and averting their eyes), while still making sure that counterplay isn't 100% reliable (still have to make occasional saving throws).

Note also the 60 yard range in AD&D, compared to 5E's pathetic 10 yard range (30').

[J-H]

A beholder, or zombie beholder, along with anything that's resistant to non-magic weapons. All of the party's weapons are now non-magical, and who really carries around that many silver or adamantine weapons?

Bonus points if you make the zombie beholder invisible, and order it to just keep its antimagic eye on the party or a specific area and not bite stuff. No magic = no detect invisibility.

[loki_ragnarock]

If you want the Catoblepas/Babau encounter to be less awful, the best way is to *add* a monster. Mostly because it increases the level of PCs about to face the encounter by a good bit.

But if what you add is Banderhob (CR5 Volo's p. 122)... you've added something that will specifically target things that are bad at strength saves/checks. It has a 15ft tongue attack that forces a strength save for forced movement (which auto-fails if target is stunned), that can be immediately followed by a bite attack that auto grapples, and next round grappled creatures get swallowed and taken out of the fight. Combined with it's low key but absurd mobility, it's also capable of protecting any vulnerable allies by psuedo teleporting, using it's 15ft tongue, and pulling threats away. Or using it's 15 ft tongue and absurd mobility to pull creatures *into* the Catoblepas poison aura.

So while the Catoblepas targets characters not specialized in constitution, the Babau mitigates typical strong types, the Banderhob steps in to screw the weak that remain.

This makes it a hard encounter for 4 level 9 PCs by the numbers. It's still perversely more fair than the other, as level 9 characters are unlikely to be straight murdered by the Catoblepas with one action, but it's still got some potential to be challenging once the Banderhob swallows someone and just leaves with them in it's stomach.

[Asisreo1]

Let's hope a Pit Fiend and a Balor remain enemies. If they happen to team up, not only is brute strength something to be wary of, the Pit Fiend also has access to Hold Monster. Which includes humanoids.

Funny thing about Hold Monster, if you get hit, you get paralyzed. If you get paralyzed, all hits on you are auto-crits. If the Balor hits you with his sword, he does triple damage dice. That's an immediate 89 damage not including his Whip attack which will do an extra 43 damage for a total of 132 damage in a single round. If you are a Paladin with max Wisdom and max Charisma at level 20, you still have a 25% chance of being hit by the initial Hold Monster save, let alone characters with the misfortune of only having wisdom max and proficiency (50%) or characters with a +0 to Wis and no proficiency (0%).

A very high-level challenge, but somewhat tricky if unprepared regardless.

[loki_ragnarock]

This one is really about asking yourself a question:

Do my players double-tap?

Devourer (CR 13, Volo's p.138) and Orcs (CR1/2, MM p.246)
At the level this is every really going to be interesting (5 orcs is hard for 4 level 14, 9 orcs is hard for 4 level 16) the characters will be able to mow through the orcs like a scythe through wheat. Or at least bring them to zero hp very easily... but how many players make sure they aren't just lingering through failed death saves in the heat of combat? Have your Devourer hold it's Soul Rend ability until a bunch of orcs have gone down; it's an extra 10 damage per not quite dead orc. Those orcs will get a failed death save as a result of taking that Soul Rend damage; all the better to eat them with, regain hp, recharge Soul Rend, and generate a new zombie to harass the PCs with.

A couple of enhanced Soul Rends can really swing an encounter from "this is easy" to "oh no." Even at those levels, adding 50 to 90 raw damage to an AoE is going to hurt.

They'll probably survive. But they might burn some attacks on double-taps in the future.

[Biffoniacus_Furiou]

Gauth beholders that fly out and attack when the party is going across a rope bridge. They're safe from melee attacks, and they have a push ray that can knock them over the side.

A Drow Mage or other spellcaster and one or more Umber Hulk. Use Web or Black Tentacles or similar to trap opponents and prevent them from retreating, and put the Umber Hulk(s) in their path to block them from reaching the spellcaster. If they want to use ranged attacks on the spellcaster, they can't look at him without looking past the Umber Hulk(s) and will be subject to its gaze attack.

[tomjon]

Beholder and trolls. Good times

[Asisreo1]

I admit that Hydroloths and The River Styx is cheating (in respect that it isn't original)...but its too good not to at least mention.

[Unoriginal]

Orc Red Fangs of Shargaas work great with any monster who can provide magical darkness without being affected by it. In particular, a Dhergoloth or Yagnoloth leading a group of Red Fangs can unleash the pain pretty well (the Yagnoloth even more so if they use their Battlefield Cunning to get two Red Fangs to attack someone who hasn't had their first turn yet as a reaction).

[Dork_Forge]

My players recently completed a Star Spawn heavy arc, it was incredibly rough on them:

They were encouraged to focus on the small guys first to get rid of their aura, allowing the manglers to decimate temp hp and concentration, whilst the Hulks loomed as large enough threats to require attention at the same time. The Seer pinging a Hulk to avalanche psychic damage was devastating to a party used to being able to rely on extreme amounts of Temp hp/hp/resistance.

I also like a Vampire with a horde of wolves, just enough to be a problem and harass the caster backline whilst the martials are torn between the vampire and protecting the concentrating caster.

Wights overseeing a small horde of skeletons is fun too, half the time the PCs try to treat it as a ranged combat, then quickly switch to trying to end it quickly when the opposing force all pull out bows.

[loki_ragnarock]

If you have something heavy, especially something that can apply movement penalties like grappled or the like to keep PCs constrained into a space, add a couple of quicklings to ratchet up the difficulty. They have such an insane movement rate - 120ft - that you can keep them a couple of rooms over and they'll still be able to pop in, do an absurd amount of damage for their CR, and pop back out. Possibly even in multiple directions; they are simply that fast..

So something like an Otyugh (CR 5, MM p.248) and 4 Quicklings (CR 1, Volo's p.188) provides a hard challenge for a team of 4 level 6 PCs.

With the Otyugh getting their attention initially, the party will have to split their attention between the big thing in the room throwing some status effects on them and potentially some decent damage and readying actions to attack the Quicklings with disadvantage... each of which can push out about as much damage as the Otyugh. With something just shy of 100 points of damage a round from the quicklings, they've got enough damage output to appear and suddenly bring down vulnerable PCs of that level before scattering off in every direction. They are a mobile hit squad, and PCs that don't know to expect them will probably have a few PCs down before they start to adjust tactics. And all the while, an Otyugh keeps them pinned down.

Put it in a room with four doors, one for each cardinal direction, and maybe witness that heroic fantasy trend go a little bit grim.

It's... not a nice thing to do, even to an experience party.

EDIT:
So, Quicklings get 3 attacks with an extremely high to hit and can do 24 damage between those three attacks. So they can do 96ish damage if they all hit with each blow.
So for 6th level:
A wizard with average rolls and a 16 con would have 42 hp? They've got enough damage to roll through those hp, do some double taps for an outright kill, hit a different PC a couple times, and then roll out of the room again out of sight.
A cleric with average rolls and a 16 con would have 49 hp? Same story, unless the AC is high enough.
A ranger with average rolls and a 16 con would have 56 hp? Also the same story, unless the AC is high enough.
A barbarian with average rolls and 16 con would have 63 hp? But rage would effectively bump it to 126; they can't geek the raging barbarian in a round at all.

But anybody with an 18 AC and less than 48hp? On the average they'll bring that character down in a round.
Anybody with a 16 AC and less than 57hp? On the average they'll bring down that character in a round, too.

They is some nasty, nasty little glass cannons.

[Eldariel]

Starspawn Grue + Banshee is pretty brutal, if not all that natural. Add few Pixies spamming Polymorph (and Sleep on anyone who gets Polymorphed) on the stragglers for even more hilarity.

Also, anything involving Couatls can be brutal. Change Shape gives them an incredible breadth of options and magical weapon immunity is obviously abusable with e.g. Zombie Beholders (as had been repeatedly stated in this thread). A couple of Couatls can combo buffs and offensive forms between one another for all sorts of hilarity.

[No brains]

Sea Hag and anything that can frighten.

While the Sea Hag's Horrific Appearance only works on humanoids and gives 24 hour immunity on a save, their Death Glare action can be used repeatedly on anything that's frightened for any reason. Even with a piddling DC11 Wisdom save, a spammable save-or-die is an interesting asset.

PCs should keep this in mind too! Sea Hag is one of the potential summons from Conjure Woodland Beings. Pair it with a frightening ally and clear house!

[Asisreo1]

Sea Hag and anything that can frighten.

While the Sea Hag's Horrific Appearance only works on humanoids and gives 24 hour immunity on a save, their Death Glare action can be used repeatedly on anything that's frightened for any reason. Even with a piddling DC11 Wisdom save, a spammable save-or-die is an interesting asset.

PCs should keep this in mind too! Sea Hag is one of the potential summons from Conjure Woodland Beings. Pair it with a frightening ally and clear house!
The sea hag allying with a scarecrow which not only frightens but also paralyzes you without an immunity save can be devastating for the party that forgot to bring their paladin or cleric.

[loki_ragnarock]

If you start with a monster that can impose the incapacitated, stunned, or paralyzed condition, add some Vargouille for a Chef's Kiss.

The Vargouille can throw down what is a genuinely mean spirited status effect on incapacitated victims.

So if - for instance - you had a Corpse Flower (CR 8, Mordy's p.127) with what amounts to an incapacitating aura and a pack of 4 Vargouille (CR 1, Volo's p.195), you've got a hard fight for a group of 4 level 9 PCs. All of the monsters involved are immune to the other monster's effects, and while the DCs are relatively low for this level, if anyone gets incapacitated, they're getting a Kiss. A DC 12 Charisma save isn't that bad, but if you're having to make it 4 times in a row or start losing charisma until you die things have potential to turn grim pretty quick. There's a way to throw it off track, but if that spell wasn't prepared then the cursed PC is likely to succumb before any long rest could possibly finish.

The party will probably triumph... but at what cost, and to who?

This one is a little swingy; if nobody succumbs to the stunning or incapacitating effects, it's a cake walk. If anybody does, it's a gross way to die.

[vexedart]

Shock lizards and shambling mounds in knee high water