I've seen it and think they did a great job. I love the whole Slender Man mythos, even though it got started on the SA forums. They've mentioned doing a sequel, but I dunno if they can make it as good as this.
Then I'm sure you'll like this junk I tossed together:
Slender Man
Large Monstrous Humanoid
Hit Dice: 14d8+42 (105 hp)
Initiative: +22
Speed: 60 ft. (12 squares), climb 30
Armor Class: 37 (-1 size, +12 Dex, +1 dodge, +6 foresight, +9 natural), touch 28, flat-footed 37 (Improved Uncanny Dodge)
Base Attack/Grapple: +14/+28
Attack: Slam +32 melee (1d6+4/18-20)
Full Attack: 2 slams +32 melee (1d6+4/18-20) and 4 tentacles +27 melee (1d3+2)
Space/Reach: 10 ft./10 ft. (20 ft. with tentacles)
Special Attacks: Augmented critical, favored prey, slender reach, stalker
Special Qualities: Canny senses, damage reduction 5/magic and slashing, darkvision 300 ft., evasion, foresight, hide in plain sight, immunity to fear, improved uncanny dodge, quickness, see invisibility, skillful step, slight build, spell resistance 22, unfettered, unholy grace
Saves*: Fort +11, Ref +27, Will +18
*see Unfettered (Ex)
Abilities: Str 19, Dex 35, Con 16, Int 22, Wis 18, Cha 21
Skills: Balance +20, Bluff +13, Climb +14, Escape Artist +17, Hide +37, Intimidate +32, Jump +11, Listen +23, Move Silently +37, Search +6, Sense Motive +15, Sleight of Hand +12, Spot +23, Tumble +35
Skill Tricks: Acrobatic Backstab, Back On Your Feet, Corner Perch, Never Outnumbered, Nimble Stand, Slipping Past, Spot The Weak Point
Feats: Blind-Fight, Combat Reflexes, Dreadful Wrath(b), Imperious Command, Improved Initiative(b), Large And In Charge, Multisnatch(b), Power Attack, Spring Attack(b), Weapon Finesse(b)
Challenge Rating: 11
This being appears humanoid, but extraordinarily thin and tall, its arms and legs elongated to a frighting degree. It wears a strange black uniform of unknown design or material, with a white undershirt that is partially covered by a dark red strip hanging from the neck. Its face is featureless.
Slender Man is a bizarre and unsettling entity, his purpose as unexplained as his origin. It is well-known, however, that he prefers to stalk forest or foggy roads while on the hunt for children. What he does with his helpless prey has never been discovered, but once kidnapped, they are never seen again. Slender Man's limbs can bend and elongate to ridiculous degrees, and he's also capable of extruding a dozen or more tentacles from his back to aid in travel or battle (he . Those who witness the motions of his slender arms are entranced, and cannot resist accepting his evil embrace. Slender Man seems to choose his victims days or weeks in advance, where they may experience nightmares of a faceless man with long, thin arms.
COMBAT
Slender Man prefers kidnapping over killing, so when pressed he usually disappears from sight and flees. If his foes are persistent, however, he attempts to hypnotize the attackers one at a time so he can carry one away from her allies to be slain in peace. If this tactic proves unreliable, Slender Man goes for the 'lightning strike' approach: like a volley of blackened crossbow bolts he pummels them and escapes to evoke dread from just beyond any survivor's eyesight. He will repeat this attack, for hours if necessary, until they are all dead or run cowering back into the light. If cornered and unable to hide or retreat, Slender Man will not hesitate to stand and fight, bringing the full brunt of his attacks onto creatures he ascertains to be the most dangerous -- with a preference against magic users as more mundane opponents have a difficult time landing hits on Slender Man's superhuman speed and agility. At first he will try to make as many enemies cower before him as he can (using the synergy of Dreadful Wrath, Imperious Command, and Never Outnumbered). Afterwards, he tries to remain outside of everyone's reach, tripping and disarming anyone he isn't trying to kill that round.
Augmented Critical (Ex): Slender Man's slams threaten a critical hit on a roll of 18 or higher.
Canny Senses (Ex): Slender Man sees eight times as well as a human in shadowy illumination, four times as well in normal light, and has darkvision out to 300 feet.
Evasion (Ex): As the monk class ability with the same name.
Favored Prey (Ex): Slender Man gains a +4 bonus on Bluff, Listen, Sense Motive, Spot, and Survival checks, and +4 on damage rolls against humanoids of any subtype (not figured into the statistics above).
Foresight (Ex): Slender Man's combat prowess is almost precognitive. He gains a foresight bonus equal to his Intelligence modifier to: armor class, attack rolls, and initiative.
Hide In Plain Sight (Ex): As long as Slender Man is within an area of at least shadowy illumination, he may use the Hide skill, even while being observed.
Hypnotic Presence (Su): Any creature that sees Slender Man extending his limbs (such as when he uses Slender Reach) must make a DC 22 Will save or enter a hypnotic state, where it can do nothing but move at its normal speed into Slender Man's outstretched arms. Slender Man may make a grapple check against such hypnotized creatures as a swift action. A creature may repeat the save if it is harmed in any way (such as an ally striking it in the face). This affect immediately ends if Slender Man makes any attack against the creature other than to grapple (he may still attack other creatures without breaking the effect). Any creature that makes the save becomes immune to this ability for 24 hours. This is a mind-affecting effect.
Improved Uncanny Dodge (Ex): As the barbarian class ability of the same name.
Quickness (Su): Slender Man is supernaturally fast. He can take an extra standard action during his turn each round. Furthermore, Slender Man is treated as if constantly hasted (already figured into the statistics above).
See Invisibility (Su): Slender Man can see invisible and ethereal creatures, as the spell see invisibility (caster level 20th).
Skillful Step (Ex): Whenever Slender Man makes a 5-foot step, he moves up to 15 feet. It is the same as a 5-foot step in every way except for the distance covered.
Slender Reach (Ex): As a move action, Slender Man can extend his reach to 20 feet (40 feet with his tentacles) and his base and climb speeds increase by 30 feet (becomes 90 ft. [18 squares], climb 60 ft.) until the beginning of his next turn. When using Stalker (see below) his speed stays the same.
Slight Build (Ex): Slender Man is considered one size category smaller (Medium) in regards to special attacks except for grappling (e.g., trip, Large And In Charge feat).
Stalker (Su): At-will as a standard action which provokes an attack of opportunity, Slender Man may become invisible (as the spell greater invisibility [caster level 20th]; unaffected by the spell invisibility purge) and incorporeal. He loses his normal and climb speeds but in in their place he has a fly speed of 20 ft. (perfect), trades his natural armor (only his permanent natural armor, not temporary bonuses from spells, equipment, etc.) for deflection, and loses his Strength score and slam and tentacle attacks but gains an incorporeal touch attack (reach same as tentacles) for 2d6 damage. He may become visible and corporeal again as a swift action, and he must wait 1 minute before he can use this ability again.
Unfettered (Ex): Slender Man gains a +4 bonus (Fort +15, Ref +31, Will +22, AC 41) to any attack or effect that can afflict him with the following conditions: entangled, exhausted, fatigued, paralyzed, petrified, stunned. Furthermore, he is immune to Dexterity damage and drain.
Unholy Grace (Ex): Slender Man gains a bonus to all saving throws equal to his Charisma modifier.
Skills: Slender Man gains a +4 racial bonus to Bluff, Intimidate, Sense Motive, and Tumble checks, and a +8 racial bonus to Hide, Listen, Move Silently, and Spot checks. He has a +8 racial bonus on Climb checks and can always choose to take 10 on a Climb check, even if rushed or threatened.
