Gary Gygax often had a thing for strange juxtapositions.  Take the Owlbear, for example.  A cute, cuddly bear with the face of a freaking owl.  I mean...why?  Other than the fact that it easily captures the hearts of every adventurer I play with, even as its powerful claws rend the onlookers in twain, its rhyme and reason are nestled in the grand plans of its creator.  
  However, some beasties follow a logical evolution.  If elves, then what about dark elves?  If these "Drow" exist, what do they worship and why?  How can such worship be rewarded, or scorned?  This is more the case of the tragic Drider.
  In Faerun, the mystical canonical realm of Dungeons and Dragons's published materials and adventures, the Drider is a product of chaos and evil.  Tied directly to those scorned by Lolth, the Spider Queen, a Drider is the result of a Drow insulting or betraying the deity.  Driders are cursed reminders of the power of Lolth, and are equally feared and scorned by the Drow population.

A Drider is a terrible juxtaposition of a Drow warrior and a giant spider, where the upper half is a humanoid elf and the lower, well, is a freaking giant spider.  Powerful and dangerous, driders are accomplished fighters that make use of their versatile movement and superior size.  Walking on walls, trapping foes, and some even casting spells, a Drider is a deadly opponent against an unsuspecting party.
  By the book, these entities enjoy only the standard boons of their elven nature, but have a pretty decent AC (19 on most).  Innate Spellcasting is helpful, and with three attacks to spare, they can cut down a Player Character pretty quickly.  In packs of 2 or more, with a Drow strike team on the ground, a tactical group of Drider can overwhelm a party from the safety of the ceiling and the distance of their longbows.  Do not underestimate them; to do so might just be the TPK you're looking for.

Lolth may be vicious to her followers, but I find it strange to think that those that displease her would be twisted into a visage that most resembles her.  In fact, I'd think such an outcome to be quite the opposite.  Would not a vicious deity bless those that most please her with the great power inherent in her favorite creatures?  To grant them but a piece of the power she knows from beyond the veil, that they may better serve her fearsome wishes in the material plane.
  It is this driving belief that created the Thirteen Coins.  Thirteen prime specimens of great Drow stock, or perhaps a few of different make, that have completed the Sins of the Spider - a grueling test of wills, might, and devastating physical and mental tasks.  Seekers of the Coin perform these tasks in pursuit of greater power, following a grand vision of the goddess, who bestows upon them more and more innate abilities - all the while twisting them further toward her ideal.
  For every Seeker, the tasks are different, but each serve the greater scheme of the master.  If they complete the Seventh Sin, Lolth may bestow upon them one of her Coins; a piece of prime power, embedded in the body of her follower.  In this way, the Coin becomes an extension of the goddess, and another form of influence she can exude upon the world.
  Coins are resilient and devastating creatures, but they are not unkillable.  If ever they are bested in battle and killed, the Coin is left behind to tempt the victors with visions and power.  Destroying such an artifact is difficult and draining.  
  Such trouble to discard such a thing.  Besides, wouldn't you rather...keep it?

See you at the table, friends.
​-Adamus

The archdevil looms above you, inspecting the burning blood that drips from his face.  The same boiling red drips from your blade as a grin curls across your lips...but its booming bass shakes you to your core as it speaks to the air around you.
  "Azolonia.  This mortal has requested his demise.  Kindly remove his head for me."
   A shockwave of dread spirals up your spine as tendrils of black smoke and scents of sulfur spur into your peripheral.  You whip around and stare into the red eyes of a statuesque form; alabaster skin and striking beauty, stylized black armor gleaming with the firelight surrounding you.  A pair of gigantic black wings stretch and flex behind her as she draws an exquisite, vicious blade from a scabbard, a grin curling across her lips.  Her voice is menacing silk.  "Of course, my lord."

The Erinyes is a powerful, disciplined devil warrior that serves the pit fiend masters of the Nine Hells.  They are dangerous, tactical, mobile, and vicious.  Masters of martial combat, each is skilled with bow and sword alike, and many use magical ropes of entanglement to ensnare powerful foes.
  Erinyes, despite their gladiatorial or knight-like visage, are often mistaken in use and sight for Succubi or Incubi.  And this could not be further from the truth.  Ignoring the fact that both would be at each other's throats, the Erinyes does not exude allure or seduction.  They are militant powerhouses among the devilish culture, and command immense respect and fear, more likely to kill or enslave with blade and chains than to charm you into defeat.  
  Only subservient to their chosen masters, an Erinyes swoops down from the skies on red and black wings to strike down those who dare threaten or insult the ideals of Asmodeus or the edicts of their masters.  When not beheading mortal fools, an Erinyes can patrol the fortress of their master, or otherwise move freely through the dissonant cities of Hell.  However, if need for their presence arises, their master only needs to speak their name and they are pulled to their aid immediately.
  So beware, small ignorant traveler.  Assume every Pit Fiend you pick a fight with has at least one Erinyes looming in the shadows behind you.

Though predominantly female in representation, an Erinyes can also be male.  No matter their gender, they are an imposing force of statuesque, athletic physique in stylized armor.  
  Their massive wings net them an impressive Fly speed of 60 feet and with a decent pool of hit points coupled with a base 18 Armor Class, these devils are hugely mobile and dangerous.  Their heroic array of stats are not to trifled with, either, sporting three 18's in Strength, Constitution, and Charisma, with no other stat going below a 14.  Higher than average Saving Throws, Immunity to Poison and Fire damage, as well as Resistance to Cold, and non-magical/non-silvered physical damage, plus TELEPATHY out to 120 FEET???  Yeesh.
  Three attacks in a round, with Parry options, extra poison damage on their "hellish" weapons, plus Magic Resistance (good luck, Wizards)...  These boys and girls are going to be quite a fight no matter the terrain.

In Ionian lore, an Erinyes is already a powerful entity, but there are some who aspire to even greater power.  An Erinyes, male or female, serves a devil master or a general oath to Asmodeus, but there is a grand order of Erinyes who command even more clout and respect among the greater and lesser devils.  These are called The Furies.  
A cohort of nine sister generals, each serving the Archduke or Archduchess of each layer of the Nine Hells.  These Erinyes have earned the title of Fury, and command legions of lesser and greater devils as grand warriors and tacticians in service of their masters.  The more they please this master, the more power and abilities the archdevil passes onto the Fury.  Meaning, the longer a Fury serves their master in good standing, the more power they may yet wield.
  This creates distinct opportunities to express a power difference between a standard Erinyes and a Fury.  Players may come in contact with a Fury flanked by three other Erinyes; her Seconds.  It is very clear that this one, adorned in stronger armor with unique weaponry, as well as vicious helm, is different than the others that surround her.  Maybe she has spell casting abilities, like war magic, or wields a legendary weapon, bestowed upon her by her Archduchess.  And though such a sight may fill the head of an adventurer with glittering prizes, such gifts can also grant higher proficiencies, saving throws, extra attacks, higher resistances.  Heightened skill earns expanded power.  
  Just know what you're getting into, grasshopper.

Welcome to Hell.
See you at the table.
​-Adamus

There are dark machinations that resonate and ripple across the ages of Io, and in this machina innocent people can find themselves crushed within the gears.  These undeserving souls might find dreadful purpose in this false resurrection, and revel in their unkillable nature.  However, every rebirth is a gift granted by an extra-planar entity, god, devil, or something else.  And, like so many elements of the Weave in Ionian lore, there is a cost to such gifts...
  The concept of an undead hero, neutral or not, exists in my world without a doubt.  Revenants are certainly not common, but they aren't unheard of.  Always seeking that greater depth of immersion and storytelling, those that do reveal themselves are never grunts or shambling corpses.  They are aware, and might have already taken steps to hide the fact that they may be slowly decomposing (herbs, liquor, formaldehyde).  Some have actively injected themselves with healing potions, syrupy elixirs of vitality, or taken to consuming infernal blood to cease the flow of rigor mortis.  And all are well aware of the passage of time - and how long remains before they turn to dust.  They may seek help from our heroes, allies to defeat their nemesis, or perhaps they've been down this road before, and have given in to their damnation.  
  My players have met two Revenants before, but I don't it was ever revealed to them (in secret or otherwise), and they will definitely show up again.  Can a player-character be a Revenant?  Anything's possible.  There's too much espionage and assassination in my world for an Archfey to not take advantage of a poor, unfortunate soul every now and then.  However, that is something that will be explored and revealed during play, not before.  No one goes in thinking they're going to become a zombie Clint Eastwood...

See you at the table.
-Adamus

Man.  I'm tired.  What I wouldn't due for some CAFFEINE.  ;)

Some baddies you find just hold a special place in your heart.  Maybe you often fall back on them because they're so versatile, or you save them for that key moment when they'll be most effective.  Could they be a striking nemesis, a freak chance encounter, or a surprising subversion of expectation?  
  I use a lot of monsters, and I make a lot of my own (that's another post altogether), but none so far have had such an "OH CRAP" moment from my players in recent games as the Remorhaz.

The Remorhaz is a traditionally arctic monstrosity.  A predator preying on elk, polar bears, and other creatures that wander into their territory.  They burrow deep into snow or ice, lying in wait for the faint vibrations of creatures moving above them.  While hidden, it can raise or lower its body temperature, keeping the snow or ice around it from melting, or allowing it to glide through the cold tunnel.
  A Remorhaz nest is quite a find, especially if you are a frost giant, as the young Remorhaz can be trained from hatching to obey commands and guard your citadels.  Some might even become mounts for other creatures.  Be careful if training these beasties, though; they are adept at swallowing their victims...

The Remorhaz has become recently fascinating to me, and not just because of their mechanical capabilities.  Residing in the grand north of the world, somewhere beyond the Wynnrik Region, the Remorhazes and their ilk would have been one of the first batches of creatures to encounter menacing Brood as they fled the collapsing Shadowfell at the turn of the 6th Age.  This means that the once dormant, territorial creatures, fought, failed, and were corrupted by the impending swarm of shadow monsters.  What came out of such a clash was an even more formidable foe.

I have a few players it seems with a penchant for getting eaten, and with an ability like Swallow, this number continues to rise.

On their turn, a Remorhaz makes a Bite attack against a creature it is grappling (snake-like body, go figure).  If the attack hits, you're looking at 6d10+7 piercing damage PLUS 2d6 fire damage, AND the creature is swallowed.  While swallowed, they are considered blinded and restrained, and will suffer 6d6 acid damage at the start of each of Remorhaz's turns.

Now, that's pretty awful.  However, your allies can deal damage to this thing while you're in its gullet.  Deal enough damage in a single turn and the thing has to make DC 15 Constitution Save or regurgitate you.  ...HOWEVER, if this thing swallowed you BEFORE it moved, it can now burrow 20 feet down (movement speed).  Without a player with Sentinel, you're in BIG trouble if they can't hit it hard enough with attacks of opportunity.  
  If you're still conscious, you might be able to get yourself out.  Restrained only brings your speed to 0, gives others advantage on attacking you, and your attacks and Dex Saves have disadvantage.  You can engage in trying to hack your way out (which at higher levels is completely kosher), cast a spell, and so on.  But if the odds aren't in your favor, your body might be SOL.

Let's shut down that Fireball and Cone of Cold immediately, shall we?

Every time a creature touches the Remorhaz or hits it with a Melee attack while within 5 feet of it takes 3d6 fire damage.  Every hit.  Not every turn, or every round.  EVERY.  HIT.
  This one is nasty.  True, average damage here is only 10 fire, but it can add up quick.  Imagine your Monk suffering 40 damage just for smacking the creature with their Flurry of Blows; sure, the thing can't take Reactions now, but the martial artist is melting.  It forces you to pay attention to a creature's mobility, economy, and range - so YAY for tactics!

After their brush with the Brood, the resulting surge of necrosis and corruption moved through the species, garnering them two new curious features.  
  First is an immunity to Necrotic damage.
  Second, a plethora of pulsing, bulbous tumors and sacks that litter their bodies.  Every time the Remorhaz suffers damage (except Psychic damage), one of the boiling tumors bursts (GROSS).  Every creature within 5 feet of the creature immediately suffers 2d6 Acid damage.  Oops.  
It makes the 5-foot radius around them extra volatile, and just like before, no saving throw.  This, coupled with the Heated Body feature, can really mess with the melee attackers and how they synergize with ranged support.
​  Keep your healers healthy, you're gonna' need it.

Also, I've been painting two of them!  Trying to follow the picture in the book for once.  So far his color test is looking really nice.  Can't wait to tighten up everything, smooth the fades, and finish him up.

Stay safe and don't get swallowed.  
See you at the table.
​- Adamus

  Aboleths have ancient, flawless memories, and pass on their knowledge from generation to generation.  This quality keeps the insult of the gods fresh and alive, perfectly preserved in their minds.  They are also treasure troves of ancient lore.  These entities play the long game; calling eons of planning to bear, patient and intricate.  

Some entities in fantasy have stood the test of time.  They are either so old or so powerful that they have outlasted every adventuring party that has sought their ruin, or already stand amongst the gods and devils that rule the multiverse.  Ancient dragons, demon lords, aberrations that rule the Underdark...these and so many more fill the world of fantasy with legend.

Many legendary creatures are tougher than your average beastie, and show that in their Legendary Resistances.  Three times per long rest, if a creature with this feature fails a saving throw, they can choose to succeed instead.  This pisses off my players to no end, but this is a great mechanical representation as to why these things have survived as long as they have.  An ancient being wouldn't be able to be charmed by one unlucky roll out of the gate; it has some fortifications against that.

Conversely, legendary beings are often, but not always, solo endeavors.  In other circumstances, such encounters can feel a little...one-sided.  As a party of 5-7 warriors gang up on a single creature, that's usually 5-7 swings on it before it gets its turn.  
Legendary ACTIONS provide a pseudo-set of extra turns each round for a Legendary Creature to use, simulating its great power and rebalancing the economy of the encounter.
  At the close of another creature's turn, not its own, this creature can spend 1-3 Legendary Actions to perform certain tasks, attacks, or powers, as dictated by their stat block.  Some powers burn only 1 LA, while others can burn 3 at once, especially if the creature is attempting something very powerful.  Sometimes it's a movement or an extra attack, or a bonus spell.  Whatever it is, stay alert!  There's a reason these things are legendary.

But to be clear:
Legendary Resistances only recharge during a Long Rest, but...
Legendary Actions return at the start of the creature's turn EVERY ROUND.  
  So you might force some saves and use up their resistances...but they're just as dangerous with their Legendary Action economy.  

Location, location, location...

A Legendary being often has a place it calls its home.  A "lair," if you will.
  Such a place tends to grant them superior bonuses to their defenses, like a homefield advantage, and often pose great danger to an unprepared party.  
A Lair in a Legendary encounter acts on an Initiative count (often count 20) like a character, but you can't attack it or defeat it.  Maybe you're fighting in a volcano, and a wave of extreme heat hits you; or a pulse of necrosis randomly strikes someone within range of the dark altar of the Lich.  And many effects get worse the longer the fight goes on, so entering a Lair with a clear strategy will help keep your party alive and (hopefully) end this encounter quickly in your favor.

Pro Tip: If ever you can engage a Legendary Creature outside of its Lair, do so.  Those homefield advantages, coupled with its already frustrating extra actions and resistances, make these fights particularly nasty.

Powerful creatures, not just legendary ones, can often have extra special abilities to be aware of that set them apart from your average hobgoblin or bulette.

​INNATE SPELLCASTING
Some monsters have the ability to cast specific spells as part of their features.  These spells, unless otherwise noted, are always cast at their lowest level.  If it's a cantrip, we can assume the creature's challenge rating (CR) as its level if we need to determine damage (unless it's otherwise noted). 
  Innate spells often have other restrictions, like "target self" or "Reaction only." 

SPELLCASTING
A monster with the Spellcasting feature is considered to have a spellcasting level and an arsenal of spell slots, as if they were a player class.  Such a creature can choose to cast spells at higher spell slots, just as a player might, giving a large bredth of caster flexibility (and making them very dangerous).  

PSIONICS
Psionics is a form of spellcasting that allows a monster to cast spells using only the power of its mind.  This tag can be attached to both Innate and standard Spellcasting, and carries no additional rules, but other parts of the game might refer to it. 
  Assume, though, that a spell cast using Psionics does not require components.  ;)

And there you have it!
Next time, we delve into the depths and visit one terrifying little beastie.  I mean it, this thing's the stuff of nightmares!
See you at the table.
​-Adamus

Last week we took a look at the multitude of Monster Types, now let's take a look at the terminology surrounding how they MOVE and how they SEE.

BURROW
A monster with a burrowing speed can tunnel through sand, earth, mud, or even ice!  Bad news on a tactical map, but the monster can't burrow through solid rock unless it has a feature that says so.

CLIMB
Climb speed lets the creature scale vertical surfaces using all or part of its movement, and they don't have to spend extra movement in order TO climb.

FLY
Monster with fly speeds can use that movement to, you guessed it, FLY.  And some monsters have the ability to Hover, making it difficult to knock them out of the air.  Any decently smart creature with a fly speed (and a breath weapon) should be feared on a tactical battlefield.

​SWIM
Well, these are getting simple.  Creatures with a swim speed can swim their speed!  And they don't even have to use extra movement...  Who'da thunk?  Good to note, though, that a swim speed can only be used in a liquid; a semi-solid material, like mud, does not support a Swim speed (Burrow would be more appropriate), but in the same vein a Burrow speed does not allow you to swim (without costing extra movement as normal).

BLINDSIGHT
A monster with Blindsight can perceive its surroundings without relying on sight, depending on the radius.  Creatures without eyes, like an ooze or grimlock, will usually have this sense, as do creatures that might use echolocation (like a bat) or something with heightened senses (like a dragon).  
  A naturally blind monster might also use this term to indicate the MAXIMUM RANGE of its perception.

DARKVISION
A creature with darkvision can see in the dark within the specified radius.  Just like with player characters, they can see in dim light as if it were bright like, and in darkness as if it were dim light.  And, just like PCs, the monster can't discern color palettes, only shades of gray.  Expect creatures who tend to live underground to have this special sense.

TREMORSENSE
​A monster with Tremorsense can detect and pinpoint the origin of vibrations within its specified radius, provided that IT is not in contact with the same ground or substance.  No, it cannot be used to detect flying or incorporeal creatures.  Expect monsters that tend to burrow, like an Ankheg or Umber Hulk, to also have this ability.

TRUESIGHT
A popular thing among high-level players, a creature with Truesight can see (out to a certain range) in normal and magical darkness, see invisible creatures and objects, automatically detect visual illusions and succeed on saving throws against them, and perceive the original form of one who is a shapechanger or someone transformed by magic.  Furthermore, the creature can see into the ETHEREAL PLANE out to the same distance.  A few ancient or psionic creatures might have this ability, but it is much more rare.

​TELEPATHY
This is a magical ability that allows a creature to communicate mentally with another creature within the specified range.  The contacted creature doesn't need to share a language in order to communicate, but it needs to understand at least one language (so the Google Translate has something to do).  A creature without telepathy can still receive and respond to telepathic messages, but can't initiate them.  
  A telepathic monster doesn't need to see the contacted creature and can end the contact at any time.  The contact is also broken if the two creatures ever exceed the range of the sense.  It often goes without saying, but contact is broken if the creature is incapacitated.  
Note: A telepathic creature within an Antimagic Field or another location where magic does not function will not be able to send and receive telepathic messages. 

Legendary Creatures, Lairs, and what the heck that all means.  
See you at the table, sipping on my coffee.
​...Gods I need more coffee...
-Adamus

There are a plethora of creatures that dominate the D&D multiverse.  Some haunt your nightmares, while others inspire your dreams.  They pour from beyond the stars and leak from the depths of the underworld.  And I love them all.

And, not unlike Pokemon, there are many different types (though I wouldn't recommend catching all of them).

UP NEXT
Before we delve into our individual monsters, we'll first identify and define what makes them special in how they move and sense, and then understanding what makes some of them LEGENDARY.  After that, we'll start moving through nearly 30 years of lore.  Let's get cookin'.

I'll see you at the table.
...With a cup of coffee.
-Adamus