Demon, Babau
This emaciated figure looks like a horned human skeleton smothered within a bone-tight hide of slimy leather.

BABAU (CR 6; XP 2,400)
CE Medium outsider (chaotic, demon, evil, extraplanar)
Init +5; Senses darkvision 60 ft., see invisibility; Perception +19
Defense
AC 19, touch 11, flat-footed 18
(+1 Dex, +8 natural)
hp 73 (7d10+35)
Fort +10, Ref +6, Will +5
Defensive Abilities protective slime; DR 10/cold iron or good; Immune electricity, poison; Resist acid 10, cold 10, fire 10; SR 17
Offense
Speed 30 ft.
Melee 2 claws +12 (1d6+5), bite +12 (1d6+5) or longspear +12/+7 (1d8+7/x3), bite +7 (1d6+2)
Space 5 ft.; Reach 5 ft. (10 ft. with longspear)
Special Attacks sneak attack +2d6
Spell-Like Abilities (CL 7th; concentration +10)
Constant—see invisibility
At will—darkness, dispel magic, greater teleport (self plus 50 lbs. of objects only)
1/day—summon (level 3, 1 babau at 40%)
Statistics
Str 21, Dex 13, Con 20, Int 14, Wis 13, Cha 16
Base Atk +7; CMB +12; CMD 23
Feats Combat Reflexes, Improved Initiative, Iron Will, Skill Focus (Stealth)
Skills Acrobatics +11, Climb +12, Disable Device +11, Escape Artist +11, Perception +19, Sense Motive +11, Sleight of Hand +11, Stealth +22; Racial Modifiers +8 Perception, +8 Stealth
Languages Abyssal, Celestial, Draconic; telepathy 100 ft.
Ecology
Environment planes (Realms Beyond)
Organization solitary, pair, or gang (3–8)
Treasure standard (longspear, other treasure)
Special Abilities
Protective Slime (Su) A layer of acidic slime coats a babau's skin. Any creature that strikes a babau with a natural attack or unarmed strike takes 1d8 points of acid damage from this slime if it fails a DC 18 Reflex save. A creature that strikes a babau with a melee weapon must make a DC 18 Reflex save or the weapon takes 1d8 points of acid damage; if this damage penetrates the weapon's hardness, the weapon gains the broken condition. Ammunition that strikes a babau is automatically destroyed after it inflicts its damage.

The babau is an assassin, a murderer, and a sadist—certainly not traits unusual in the demons, yet the babau's penchant for stealth and surprise sets it apart from its generally less-subtle kin. With no need to eat (although most babaus relish the flavor of mortal meat on their thin, raspy tongues), a babau can wait in ambush for years or decades—their inhuman patience in anticipating a well-conceived murder also setting them apart from the other denizens of the Abyss. Babaus obsess over the act of killing and take great pride in their grisly art, often leaving behind some form of grim marker or obscure signature, whether it be a distinctive modus operandi, an unnerving token, or other profane evidence.

A babau typically carries a longspear or other weapon with which it can strike at foes beyond its normal reach, but given the opportunity, a babau prefers to fight with its teeth or claws. The foul, caustic sludge that constantly seeps from their flesh prevents them from wearing armor unless it is specially treated or resistant to acid.

A babau is 6 feet tall but weighs only 140 pounds. They form from mortal souls of lone killers—those who, in life, took pleasure in more personal and intimate murders. Loosed upon the Material Plane, a babau often finds itself in the same role, haunting the shadowy corners of the world as remorseless assassins.