Su-Monsters are a race of man-sized, predatory primates traditionally possessed of potent psionics. They are one of the more obscure but old-school Dungeons & Dragons monsters, having first appeared in Supplement III: Eldritch Wizardry alongside more famous monsters like Orcus, Demogorgon, most of the iconic Tanar'ri such as the Succubus and the Marilith, Mind Flayers and Couatls.
Physically, su-monsters resemble large (4ft to 5ft tall) monkeys, with their prominent ribs and vertebrae protruding and giving them a deceptively gaunt or starved look. Their hands and feet are shaped the same, with each appendage consisting of three long, thick fingers and an opposable thumb, all capped with razor sharp claws that, alongside their prominent fangs, make their carnivorous nature clear. They are predominantly gray colored, but their faces and tails are black and their paws are bloody red. They are native to Faerûn as well as to Oerth, being found particularly in tropical regions such as Chult or the lands of Al-Qadim.
Territorial and predatory, su-monsters live either in family groups (two parents and any offspring), or in clans based on extended family units. They have a weird enmity for the psionically imbued, despite their own powers; su-monsters in AD&D can use the Psychometabolism Devotion of Enhancement, the Metapsionics Devotion of Psionic Sense, and three Telepathy powers; the Science of Psionic Crush and the Devotions of Mind Thrust and Psionic Blast. There is a 10% chance that Su-monsters will have one more science and two more devotions in the psychometabolic discipline, and their Enhancement and Psionic Sense abilities are endemic to them; they can use both without cost and Psionic Sense is considered to be permanently active. As a final psionic power, they are completely immune to telepathic attacks.
With these traits, it's little wonder that many believe they were created through fleshcrafting (often by merging man and monkey) by an evil cleric or wizard who had a particular enmity for the psionically adept; they can still be found in the services of evil mages and priests to this day, which only adds fuel to the fire.
Su-monsters appeared in the Monster Manual II for AD&D 1e, and the Complete Psionics Handbook & Monstrous Manual for AD&D 2e. They had an "Ecology of the Su-Monster" article in Dragon Magazine #167, and the 2e Greyhawk accessory "The Scarlet Brotherhood" establishes that the titular faction has bred a smaller version of the su-monster, called the "Su-Monkey". They only appeared in 3rd edition in a web enhancement for the infamously bad Psionics Handbook, which caused them to slip under the radar of most people. They have appeared in both 4th edition (Monster Manual 3) and in 5th Edition (Tomb of Annihilation).
Some quirk of their biology makes su-monster flesh utterly inedible; those who consume it must make a save vs. poison or be incapable of natural healing for the next week due to the toxins.
Nentir Vale Su-Monsters
In 4th edition, for the Nentir Vale setting, su-monsters were tweaked a little. In this setting, su-monsters are a fey species of beasts, having been engineered through the magical fusion of jungle monkeys and fey panthers by the ambitious wizard, Halkith. See, Halkith lived on the Isle of Dread, a realm within the Feywild home to various monsters, including Yuan-ti, dinosaurs, and savage primitives, and he needed guards for his tower. The su-monsters filled that role well... until one day a massive wave of psionic energy washed over the Isle; Halkith had created his monsters to have a psychic link, and this was overloaded by the energy wave, driving them irrevocably mad. Halkith disappeared, either fleeing his former creations or destroyed by them, and the su-monsters have spread to tropical jungles throughout the multiverse.
Ironically, these su-monsters are not enraged by psionic energy, but attracted to it. Wild su-monsters tend to gather around sources of psionic power, whilst many arcanists or psionicists have tamed them (or at least keep them as exotic and stupidly dangerous pets).
In the Nentir Vale, su-monsters are also known as the "wolves of the treetops". Their combination of speed, pack instincts, vicious claws, innate cunning and instinctive psionic attacks make them forces to be feared.
In Dragon Magazine #265, an article called "Primitive PCs" introduced what can only be described as an alternate take on su-monsters. Called Su-Folk, these primates are smarter than their bestial originals, enough so that they can communicate and reason with other races, as opposed to being unnaturally cruel and feral beasts. They are not evil, but have a tendency to fall into bad crowds; being a territorial race by nature, they are easily bartered with by malign spell-casters into serving as their guards; in fact, they're described as somewhat gullible. They're a highly community-focused race, and care little for things such as glory or wealth; most su-folk adventurers are either lost, the sole survivors of destroyed troops, hunting for psionic lore, out for revenge on somebody who destroyed their family/territory, or just looking for neat stories to tell the troop when they return.
- Ability Score Minimum/Maximum: Strength 3/18(50), Dexterity 3/19, Constitution 5/18, Intelligence 3/18, Wisdom 7/18, Charisma 3/13
- Ability Score Adjustments: +1 Dexterity, +1 Constitution, -2 Charisma
- Class & Level Limits: Fighter 9, Thief 9, Psionicist 12
- Multiclass Options: Fighter/Thief, Fighter/Psionicist, Pisonicist/Thief
- Thieving Skill Adjustments: -5% Pick Pockets, -5% Open Locks, -5% Find/Remove Traps, +5% Detect Noise, +15% Climb Walls
- Available Kits: Bandit, Savage, Scout, Forestlord, Savage Fighter, Tribal Defender, Wilderness Protector, Wizard Slayer, Psionic Specialist (Telepathy/Psychometabolism), Pioneer
- Movement Rate: 9
- Size: Medium
- Natural AC: 6
- Natural Weapons: Claw attack that deals 1d4 damage (a su-folk can make 2 claw attacks in a round, 4 if hanging by its tail), Bite attack that deals 2d4 damage
- Family Defense Frenzy: At 5th level, 1/day, a su-folk can go into a frenzy in order to protect their mate and/or offspring. This frenzy lasts for either 4 rounds (male) or 6 rounds (female), and during it, they can either make double their normal amount of attacks per round (but can only use natural weapons), or they can simultaneously engage in psionic combat or use a psionic ability whilst still attacking normally.
- Su-folk hiding within trees inflict a -4 penalty on the surprise roll of their opponents.
- By hanging by its tail from a branch or similar object, a su-folk can use all four claw attacks per round. At the DM's discretion, they can benefit from a thief's Backstab ability whilst doing so.
- Su-folk are immune to all psionic sciences and devotions of the Telepathy school.
- Their evil reputation means that su-folk suffer a +3 penalty to reaction rolls against Good forest creatures (elf, treant, centaur, etc) and a +1 penalty against Neutral ones (dryad, druid, sprite, etc).
- Su-folk must spend 1 extra proficiency slot to gain proficiency in any human weapon.
- Nonweapon Proficiencies: Artistic Ability, Direction Sense, Fire-building, Leatherworking, Weather Sense, Weaving, Juggling, Jumping, Local History, Set Snares, Tightrope Walking, Tumbling, Animal Lore, Endurance, Gaming, Hunting, Set Snares, Survival (Forest & Subterranean), Tracking