"P" is for "Prongalope"

Prongalope

No. Enc.:  1d6+2 (2d10)
Alignment:  Neutral
Movement:  210' (70')
Armor Class:  5
Hit Dice:  5
Attacks:  2 or 1 (x2 weapon, or 1 gore)
Damage:  by weapon x2, or 1d6
Save:  L5
Morale:  9
Hoard Class:  VII
XP:  1,100

Prongalopes are man-sized, nomadic giraffoids with horns that coruscate with green electricity.  They travel the wastelands in tigh-knit clans, living off the lands and bartering for what they can't scavenge...and if negotiations fail, prongalopes are not above taking what they need..

Fast and frenetic, prongalopes strike twice per round with the same weapon, melee and ranged alike.  Their natural agility gives them a base AC 5, which can be improved by shields and tech.

Prongalopes settle tribal rivalries with elaborate dance contests, and their mutations are ideally suited to this purpose..  Once a year, the beings gather by the thousands to resolve debts, disputes, divorces, and all manners of conflicts via the art of "serving".  Prongalopes will gladly "step to" PCs and "take them to the prairies" in place of combat.

Mutations:  Combat Empathy, Energy Ray (Electricity), Fragrance Development, Increased Balance, Precognition 

"I" Is For "Isothrope"

This entry is based on a monster model kit I painted up all post-apocalyptic.  And there wasn't a decent pic of the box art on The Interwebs, so consider my personal scan a gift for the masses!

Isothrope

No. Enc.:  1 (1d4)
Alignment:  Chaotic
Movement:  150' (50')
Armor Class:  4
Hit Dice:  11
Attacks:  3 (2 claws, 1 bite)
Damage:  1d8 / 1d8 / 2d6+4
Save:  L6
Morale:  11
Hoard Class:  VII
XP:  10,800

By day, isothropes are feral Pure Human derelicts who haunt the wastelands... but beneath the Mutant Future's shattered full moon, they transform into corrupted creatures akin to those of Ancient mythology.

Isothropes glow a scintillating neon, and their eyes burn with blue radioactive rage.  Their blackened, cracked skin sloughs off in sheets.  Tainted blood seeps from every orifice. Isothropes are always clad in the tattered remnants of radiation suits.

Isothropes are immune to radiation, toxins, and disease, and all weapons inflict only half damage [to simulate their hyperactive healing].  The creatures spread their infectious metamorphic condition as per the lycanthropy disease [Labyrinth Lord Core Rules, p. 86].  

Mutations:  Increased Senses (Hearing, Smell, Taste, Vision), Metamorph (Modified), Optic Emissions (Gamma Eyes), Regenerative Capability, Toxic Weapon ("Isothropy")

"What's Nuked, Scooby-Doomsday?" — Wendighost

Wendighost

No. Enc.:  1 (1)
Alignment:  Chaotic
Movement:  120' (40')
        —Fly:  210' (70')
Armor Class:  3
Hit Dice:  12
Attacks:  2 or 1 (2 claws, or 1 weapon)
Damage:  1d10 / 1d10, or by weapon
Save:  L12
Morale:  9
Hoard Class:  XXII
XP:  7,600

Wendighosts are burly, 8' tall, satan-browed bipeds that terrorize mountainous forests and polar climes.  Shaggy white fur makes them almost invisible in the snows, so they Surprise on 1-4 on 1d6 in such environs.

If a wendighost successfully strikes with both claws in the same round, it crushes with a powerful hug for another 2d8 damage.

Highly intelligent, wendighosts are proficient with Ancient tools and artifacts.  And they are straight-up the most malicious and bloodthirsty beasts in the Scooby-Doomsiverse, as they've been known to hurl crushing barrels, lob explosives, pitch enemies off cliffs, and even tie kidnapped victims to lumber-mangling buzzsaws!

Seriously.  They're brutal.

Mutations:  Enhanced Vision (Night), Fear Generation, Increased Balance, Increased Willpower, Psionic Flight, Reflective Epidermis (Cold)

—

[Inspired by Scooby-Doo, Where Are You! episode #17, "That's Snow Ghost" (1970)]

"What's Nuked, Scooby-Doomsday?" — Steam Demon

Steam Demon

No. Enc.:  1d4 (1d8)
Alignment:  Chaotic
Movement:  120' (40')
—Levitation:  120' (40')
Armor Class:  5
Hit Dice:  8
Attacks:  2 claws
Damage:  3d6 / 3d6
Save:  L8
Morale:  10 / 6 (see below)
Hoard Class:  XIV
XP:  2,560

Steam demons are the nastiest denizens of ruined under-cities and sewers.  The hissing fiends relish wanton cruelty and vandalism, and their ability to channel sizzling, steel-melting electricity through their claws only enhances their destructive might.

Bullies and thugs, steam demons fancy kidnapping surface-dwelling Pure Humans and Mutant Animals just for sadistic thrills.  That said, steam demons are terrified by Mutant Humans of CHA 6 or less and other "frightening" bipeds.  Their Morale drops to 6 upon encountering groups of 2 or more such beings.

Steam demons generate billowing clouds of noxious, fuchsia-hued gas that surround them in a 20' radius.  Anyone caught within suffers the effects of a Class 4 poison per round and a -2 penalty to all To Hit rolls (even if a Saving Throw Vs Poison succeeds on the damage).  And though they sport prominent wing-flaps, steam demons actually levitate, and can only reach vertical heights of 15' above the ground / floor.

Mutations:  Energy-Retaining Cell Structure, Enhanced Vision (Night), Fear Generation, Phobia ("Monstrous Humanoids") [D], Toxic Weapon ("Sulfurous Fumes")

—

[Inspired by The Scooby-Doo Show episode #10, "A Frightened Hound Meets Demons Underground" (1976)]

"What's Nuked, Scooby-Doomsday?" — Cat-Creature

Cat-Creature

No. Enc.:  1 (1d4)
Alignment:  Chaotic
Movement:  150' (50')
Armor Class:  1
Hit Dice:  7+1
Attacks:  3 (2 claws, 1 bite)
Damage:  1d6 / 1d6 / 1d8
Save:  L4
Morale:  8
Hoard Class:  XXII +2d6 jewelry
XP:  1,700

Cat-creatures are nocturnal, olive-hued felinoids obsessed with gemstones, precious metals, and shiny trinkets.  Accordingly, they are usually encountered in ruined shopping complexes, or un-plundered cemeteries (which are often bizarrely decorated with feline-centric statuary).  Rumors suggest that cat-creatures are actually normal humans who unknowingly metamorphose while sleeping, perhaps due to exposure to irradiated jewelry

Between their flowing, obscuring capes and freakish acrobatic prowess, cat-creatures are almost impossible to strike in combat.  They can make springing leaps of up to 50'.

Snarling and feral, cat-creatures are far more savage and far less crafty than the typical Scooby-Doomsday monstrosity.

Mutations:  Enhanced Vision (Night), Increased Balance

—

[Inspired by The Scooby-Doo Show episode #33, "Make A Beeline Away From That Feline" (1978)]

"What's Nuked, Scooby-Doomsday?" — Tamooka

Tamooka

No. Enc.:  1d4 (1d6)

Alignment:  Chaotic
Movement:  0' (0')
         —Fly:  240' (80')
Armor Class:  4
Hit Dice:  12
Attacks:  1 (gore)
Damage:  2d8
Save:  L6
Morale:  10
Hoard Class:  None
XP:  6,000

The nocturnal tamookas are airborne bovines that haunt the skies over prairies and badlands, and they only touch ground when sleeping.  Their fur glows a phantasmal bluish-gray, and their eyes burn with ruby malice.

The beasts can fly as fast—or faster!—as ground vehicles, but they won't pursue into tunnels or confined spaces.  Tamookas make frequent Dive attacks, and when carrying away victims, turn themselves and their quarry invisible to escape unimpeded.

Tamookas sinisterly "poach" livestock away from villages, using their Empathy mutations (which only work on creatures of animal-intelligence) to lure the beasts away.

Mutations:  Control Light Waves, Empathy (Modified), Enhanced Vision (Night), Fear Generation, Psionic Flight

—

Moodicine Man

No. Enc.:  1d4 (1d6)

Alignment:  Chaotic

Movement:  120' (40')

Armor Class:  6

Hit Dice:  8

Attacks:  1 (bite, or weapon)

Damage:  1d8, or by weapon

Save:  L8

Morale:  8

Hoard Class:  XIII, XIV

XP:  1,060

"Mooka-wonka!!!  Mooka-wonka!!!  Mooka-wonka-wonka!!!"

Moodicine men are tribal bovinoids with shaggy manes, ivory horns, saucer-sized eyes, and savage fangs  They frequently ally with a region's tamookas (even going so far as to ride them into battle), and feed upon the enthralled livestock procured by the flying bulls.  They also devour vanquished enemies!

Moodicine men reside in elaborate cave dwellings, and share their living spaces with eagles, owls, and other avians (mutated or otherwise).

Mutations:  Albinism (D), Enhanced Vision (Night)

—

[Inspired by The Scooby-Doo Show episode #11, "A Bum Steer For Scooby" (1976)]