The following material is Open Game Content from the Menace Manual SRD
Fiends appear in countless forms, although their physical characteristics often reflect some sin or other vile aspect.
Fiends share the following traits:
Darkvision (Ex): Fiends have darkvision out to a range of 60 feet. Darkvision is black and white only, but it is otherwise like normal sight, and a fiend can function with no light at all.
Allegiances: All fiends have a primary allegiance to evil. Fiends may also have an allegiance to either chaos or law.
Weapon and Armor Proficiency: Fiends receive either Archaic Weapons Proficiency or Simple Weapons Proficiency as a bonus feat. They are proficient with their natural weapons and any weapon mentioned in their entries. Fiends noted for wearing armor gain the bonus feat Armor Proficiency with whatever type of armor they are accustomed to wearing (light, medium, heavy), as well as all lighter types.
Languages: Fiends can speak Abyssal (the language of demons) and a number of additional languages equal to their Intelligence bonus. Fiends with an Intelligence of 8 or higher can also read and write these languages.
Special: Fiends cannot be raised from the dead.
Stygilor (Tumor Fiend)
Damage Reduction 5/Piercing (Ex): A stygilor ignores the first 5 points of damage dealt by any nonpiercing weapon.
Disease Sense (Ex): A stygilor can sense whether a creature is infected with a disease merely by being within 10 feet of it. It cannot sense nannite infection (see the “Etoile” entry for details).
Frightful Presence (Ex): A stygilor can use the Frightful Presence feat once per round as a free action. All creatures within 10 feet that can see the stygilor and have fewer levels or Hit Dice than the stygilor must succeed at a Will save (DC 10 + 1/2 the stygilor’s Hit Dice + its Charisma modifier) or take a –2 penalty on attack rolls, saving throws, and skill checks for 1d6+2 rounds. A successful save grants immunity to the stygilor’s frightful presence for 24 hours. Creatures with an Intelligence of 3 or lower are unaffected. This is a mind-affecting ability.
Immune to Disease (Ex): A stygilor is immune to diseases of all sorts.
Invisibility (Sp): A stygilor can use invisibility at will (caster level 6th) as an attack action. It often uses this ability to move through hospital wards unseen.
Telepathy (Su): A stygilor can communicate telepathically with any creature within 100 feet that has a language.
Wounding Gaze (Su): As a free action, a stygilor can fix its gaze upon a single creature within 30 feet. The target must succeed at a Will save (DC 10 + 1/2 the stygilor’s Hit Dice + its Charisma modifier) or take 1d4+2 points of damage, as though struck by one of the stygilor’s horrible claws. The target need not be looking at the stygilor, and wounds inflicted by this attack leave nasty scars once healed. This is a mind-affecting ability. The save DC is Charisma-based.
Stygilor (tumor fiend): CR 4; Medium-size outsider; HD 6d8+12; hp 39; Mas 18; Init –1; Spd 20 ft.; Defense 18 (–1 size, +9 natural), touch 9, flat-footed 18; BAB +6; Grap +8; Atk +8 melee (1d4+2, claw); Full Atk +8 melee (1d4+2, 2 claws) and +3 melee (1d6+1, bite) or +5 ranged; FS 5 ft. by 5 ft.; Reach 5 ft.; SQ Damage reduction 5/piercing, darkvision 60 ft., disease sense, frightful presence (DC 15), immune to disease, invisibility, telepathy, wounding gaze (DC 15); AL chaos, evil; SV Fort +7, Ref +4, Will +5; AP 0; Rep +0; Str 15, Dex 8, Con 15, Int 12, Wis 10, Cha 15.
Skills: Bluff +11, Intimidate +11, Knowledge (any one) +10, Listen +9, Read/Write Abyssal, Read/Write Language (any one), Sense Motive +9, Speak Abyssal, Speak Language (any one), Spot +9.
Feats: Frightful Presence, Improved Damage Threshold.
Advancement: 7–8 HD (Medium-size); 9–12 (Large); 13–18 HD (Huge).