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.
Murdergaunt (Whistling Fiend)
Damage Reduction 10/+1 (Ex): A murdergaunt ignores the first 10 points of damage dealt by any nonmagical weapon. In campaigns without magic weapons, the GM can either disregard the fiend’s damage reduction or apply it only to certain types of weapons (ballistic, bludgeoning, piercing, slashing, or sonic/concussion).
Fire Resistance 10 (Ex): A murdergaunt ignores the first 10 points of damage from any attack that deals fire damage.
Immunities (Ex): A murdergaunt is immune to sonic and concussion damage.
Impale (Ex): A murdergaunt that hits with one of its armspikes may choose to impale its opponent. An impaled opponent takes armspike damage each round it remains impaled (on the murdergaunt’s turn). An impaled creature must tear free of the serrated armspike to move to another square, taking 1d6 points of damage in the process. A murdergaunt must tear its armspike from an impaled opponent to move to another square or to free the limb; pulling free the armspike deals an automatic 1d6 points of damage to the impaled creature, but the murdergaunt cannot use the newly freed armspike to attack that round.
A murdergaunt can impale two Medium-size or smaller creatures at the same time; however, it cannot make an attack (or attack of opportunity) with an armspike that is currently impaling a foe.
Telepathy (Su): A murdergaunt can communicate telepathically with any creature within 100 feet that has a language.
Whistle (Su): A murdergaunt can whistle as a free action every round. Creatures within 120 feet who can hear the murdergaunt’s horrid tune must make a Will save (DC 10 + 1/2 the murdergaunt’s Hit Dice + its Charisma modifier).
Any creature that fails its Will save cowers until the whistling stops. A cowering creature is frozen in fear, loses its Dexterity bonus, and can take no actions. In addition, a cowering creature takes a –2 penalty to Defense.
A creature that saves against the murdergaunt’s whistle cannot be affected by the same murdergaunt’s whistle for 24 hours. The save DC for the whistle is Charisma-based.
Murdergaunt (whistling fiend): CR 9; Large outsider; HD 9d8+27; hp 67; Mas 17; Init +3; Spd 40 ft., climb 20 ft.; Defense 25 (–1 size, +2 Dex, +14 natural), touch 11, flat-footed 23; BAB +9; Grap +17; Atk +13 melee (1d6+5, armspike); Full Atk +13 melee (1d6+5, 2 armspikes) or +12 ranged; FS 5 ft. by 5 ft.; Reach 10 ft.; SQ Damage reduction 10/+1, darkvision 60 ft., fire resistance 10, immune to sonic/concussion damage, impale, telepathy, whistle (DC 16); AL evil; SV Fort +9, Ref +9, Will +7; AP 0; Rep +0; Str 18, Dex 16, Con 16, Int 13, Wis 13, Cha 15.
Skills: Balance +12, Climb +13, Escape Artist +12, Hide +14, Jump +13, Listen +10, Move Silently +14, Read/Write Abyssal, Read/Write Language (any one), Speak Abyssal, Speak Language (any one), Spot +10, Tumble +12.
Feats: Agile Riposte, Dodge, Stealthy.
Advancement: By character class.