They wait in the dark. Weapons clenched between fingers and carpals, musty leather over steel over bones charred a perfect black. Waiting like soldiers on revue. No one knows how long they might choose to stay in a particular spot, when they move or why. If they sense living flesh before your light touches them, then the first thing you'll see is coronas of unnatural sky-blue lighting up in the darkness ahead. Their black skulls swivel and bob in a pulsing teardrop of blue fire, empty orbital ridges and grinning jaws intermittently submerged in light. The fire crackles, smells oddly clean like what's left when a coal burns out. Their feet barely make a sound except when they run, heelbones striking stone click click click.
Most of them balance weapon and shield. Various styles of sword, battle-axes, maces, warpicks. One out of four or five might carry a two-handed sword or polearm. They coat the planks of their shields with pitch, then scrape a death's head off the black, a negative in oak or lindenwood of their grinning visages. Brigandine, mail, munitions plate, whatever their armor style it will be given a black coating. Strapped over the rags of rotted clothes, hanging loosely off their fleshless frames.
They are warriors still. They might consider you worthy to join them, but they have standards. Weak opponents (and those who are clearly not of the martial profession) will have their remains discarded contemptuously into one of the many abysses or chutes of the underworld. Those who fought well will join them to fight again. Other than this behavior they display no more intelligence than the factured, bound spirit of any animated skeleton.
They attack in bands of 4-6 (the leader of a band of six will wield a two-handed weapon and sport an extra HD). Apart from selecting the moment to ignite and strike they show no interest in tactical advantage, usually pairing off with opponents individually. Occasionally they will lower their heads and lash out with licking fire. Occasionally, pointlessly, they raise their weapons to their faces in a martial salute, as if in preprogrammed gesture.
Stupid, stupid, stupid slimes. How could such things come to be? A protean predator, semisolid and translucent as waxpaper or sugar paste. It forms and spreads in dull cellular repetition upon cold stone floors in the dark. You can see its glitter at the edge of your torch like a puddle of powderized glass. It looks like any other mysterious stain underground, until you come within a yard: then the thin membrane stands up like a wave in timelapse photos and seizes your legs. It spreads up, and binds to your skin quick as gorilla glue, and eats your hide with an embrace of dissolving acid. You'll be too busy wriggling and shrieking to get it off yourself, but a determined friend might save you with a lot of scraping.
Bad enough to get killed by a slime. The victim's indignity has just begun: now they are the mindless creature's conveyance. They've become a Waxman.
Waxmen essentially look like slumped, rounded and lumpen people in profile. Their gluey, glazed-translucent skin hangs down in pseudopod-like danglers, like runny drops frozen just before dripping off the larger mass. But you'll probably notice the bones first. Skulls, ribs, humera, femurs, radii and tibia hang disjointed, suspended in slow-motion dissolution within the gelatinous body. Eyes extend from the skull on pale nerve tethers. Lungs slough apart and intestines sag within the chest. The skin and muscles are gone and most of the small bones eaten away but the rest is exposed like a person taken apart and diagrammed. The eyes and brain always go last, for some reason.
Some people say that the person Waxmen once were lives on, but thankfully that isn't true. The bones simply give structure to the mature ooze, facilitate something like walking, allow it to reach out with gelatinous tendrils framed by disconnected arm-bones. Stabbing the organs inside does nothing. The "flesh" sweats an acid that smells like sulfur and burns at skin, but mostly they damage by blunt force, bludgeoning to death with their tendrils. If the loping, clumsy attacks actually manage to kill something the Waxman "vomits" a part of itself over the dead victim, whose decaying body provides a substrate for the next puddle-like iteration to slowly form over, like hoarfrost over blackening flesh and exposed bone until all signs of the victim pass away and there is only the spread of slime.
A skeleton outlined in a bulky manlike profile of color, shifting green to orange in blinking pulses. It lights up the underground like a lantern wherever it goes, and wherever it goes its open jaws cry tonguelessly. The shriek of a maniac, remorselessly annoying, monotonous in its panic. It intermittently pauses, as if the thing had to breath (it doesn't).
Phantommen are almost ethereal, but not quite. What they are is ghosts sheathed in ectoplasm, giving them their blobby, cartoonish outlines. Wherever they pass they leave a briny-smelling mildew or wetness (even if you couldn't hear their screaming from far off you could easily track their wet footsteps). They always run, and they don't let walls stop them. The first time you'll see one it will emerge shrieking at a full run right out of a solid stone wall, leaving a man-sized coating of slime. Then run right through you with a cold bracing shock, leaving you well-covered in clammy mucus. They will pass back through you and back again two or three times more, because Phantommen are assholes. Then they will actually start trying to bludgeon you to death (do their victims rise as more Phantommen? No one has the resolve to study these annoying specters and find out).
Fortunately, other than leaving you wet, shivering and smelling like a log rotting in an estuary, the Phantomman has no way to attack in its ethereal state. It must briefly become solid in order to strike, and it does so clumsily, giving a skilled warrior a window to hew it down (hewing a Phantomman of course, sprays more gak-like ectoplasm everywhere).
Imagine a Hobgoblin (well, the Paizo version---so, hairless, vaguely reptilian with catlike clefted mouths and bat-ears), with flesh of a deep blue, scaled and cracked like old pavement over the shoulders, forearms and other swells of muscle. Now squash that image so the creature is squat, slightly taller than a Dwarf with a barrel profile and apish, swollen arms. Give it a bow-legged stance and a frown to match its scaly jowls and deep red eyes. Now dress it in stuff you'd find at a 15th-century Goodwill with stained leather armor and a weapon on its belt.
Believe it or not, this thing is yet another type of Fairy.
Banehands are roustabouts and braggarts as many of the Fey Kindreds are wont to be. They will typically be found in remote places, ruins and heights, particularly abandoned fortresses or towers from which they can play at Lord of the Manor. They congregate in large gangs of about thirty and typically operate much like any other clan of brigands. Like all fairies, Banehands horde human coin and other wealth which they have no use for. but prize weapons, armor and liquor of any sort as the finest spoils. Unlike the other things on this list they can be bargained with and probably won't attack without favorable odds (blustering is always fine however).
They favor small, round shields and wide falchion swords or battleaxes and on average will have girded on a shirt of mail. They lack the severe allergy to metal that plagues other fairy-kindreds although by the same token they are no more resistant to injury than mortal man.
The Banehands' gimmick is that they can bestow a minor curse on their enemies (Doom, as a spell-like ability), performed with a gesture of their weapon-hand which glows with a crystal blue light as they enact the curse (hence the name!) They can use this ability once per battle. Their leaders usually have four HD and have Fumble (-20 to target's next d20 roll) as an additional once-per fight ability. Although the typical Banehand's curse isn't that potent, they do aggregate: so a single Banehand can inflict a -2 penalty on attacks, saves and skill checks on a target, and the next makes it -4 and the next -6 and so-on. Typical tactics are to isolate a target, render it nigh-defenseless with curses and then have a laugh pushing the poor sod around until they get tired and just take his stuff.
For all that they talk a big game ("Fool of a mortal, FALL before my FEY MAGICS!"), Banehands have little stomach for any fight their curses can't make easy. They also be bribed if the party is willing to trade some spare weapons or a keg of ale. They may even make for somewhat decent henchmen for the right Chaotic PC who knows how to flatter their self-image as warriors and lead them to plunder.
Out of these, Blueflames and Waxmen I came up with all on my own while I got the names Phantommen and Banehands off a random monster name generator. I imagine these being 2 HD mook monsters on par with gnolls, except possibly for Banehands who are probably funnier if they are a bit shit.