Arcanaloth (CR 17)

Medium Outsider (Evil and Yugoloth)
Alignment: Always neutral Evil
Initiative: +7 (+3 Dex, +4 Improved Initiative); Senses: Listen +19 and Spot +19
Languages: Can speak and write any language

AC: 28 (+3 Dex, +15 natural), touch 13, flat-footed 25
Hit Dice: 12d8 (54 hp); DR: 15/good
Fort +8, Ref +11, Will +14
Speed: 30 ft., fly 50 ft. (poorly)
Space: 5 ft./5 ft.
Base Attack +12; Grapple +12
Attack: Claw +12 melee
Full Attack: 2 claws +12 melee and bite +7 melee
Damage: Claw 1d4 plus poison, bite 1d6
Special Attacks/Actions: Poison, spell like abilities, spells
Abilities: Str 11, Dex 16, Con 11, Int 20, Wis 18, Cha 17
Special Qualities: outsider traits, partial immunity to spells, SR 24, yugoloth traits
Feats: Combat Casting; Empower Spell; Improved Initiative; Iron Will; Spell Focus (Abjuration)
Skills: Bluff +18, Concentration +15, Diplomacy +22, Gather Information +18, Intimidate +20, Knowledge (arcana) +20, Knowledge (the planes) +20, Listen +19, Profession (scribe) +19, Search +20, Sense Motive +19, Spellcraft +22, and Spot +19
Advancement: 13-24 HD (Medium-size)
Climate/Terrain: Any land and underground
Organization: Solitary pair, or embassy (3-4)
Treasure/Possessions: Standard

Source: Monster Manual II

Partial Immunity to Spells: Mind-affecting spells have no effect on arcanaloths.

Change Shape (Su): An arcanaloth can assume the form of any Small or Medium humanoid.

Poison (Ex): An arcanaloth's claws are coated with poison. It delivers this poison (Fortitude save DC 16) with each successful claw attack, The initial and secondary damage is the same (1 point of Strength damage).

Spell-Like Abilities: At will - darkness, fly, heat metal, invisibility (self only), magic missile, telekinesis, warp wood; 1/day - fear, major image. Caster level 12th; save DC 13 + spell level.

Spells: An arcanaloth can cast arcane spells as a 12th-level sorcerer (spells known 9/5/5/4/3/2/1; spells/day 6/7/7/ 7/6/5/3; save DC 13 + spell level, or 15 + spell level for Abjuration spells).

Summon Yugoloth (Sp): Once per day, an arcanaloth can summon another arcanaloth with a 40% chance of success. Summoned creatures remain for 1 hour, then return whence they came. A yugoloth that is itself summoned cannot use its own summon ability for 1 hour.

Outsider Traits: A yugoloth has darkvision (60-foot range). It cannot be raised or resurrected.

Yugoloth Traits: A yugoloth is immune to poison and acid. It has cold, fire, and electricity resistance 20. Yugoloth can communicate telepathically with any creature within 100 feet that has a language.

Evil Subtype

A subtype usually applied only to outsiders native to the evil-aligned Outer Planes. Evil outsiders are also called fiends. Most creatures that have this subtype also have evil alignments; however, if their alignments change, they still retain the subtype. Any effect that depends on alignment affects a creature with this subtype as if the creature has an evil alignment, no matter what its alignment actually is. The creature also suffers effects according to its actual alignment. A creature with the evil subtype overcomes damage reduction as if its natural weapons and any weapons it wields were evil-aligned (see Damage Reduction).

Yugoloth Subtype

Possibly the greediest, most selfish beings in the Outer Planes, yugoloths reign supreme among the evil outsiders of Gehenna.

Traits: A yugoloth possesses the following traits (unless otherwise noted in a creature's entry).