Well I asked for apes and got them!
And now for something completely utterly mind numbingly frightening..And different.
Elder Magical Beast as stated above is from the free chapter of Legends and Lairs: Monster's handbook. Legendary Wolf is from Masters of the Wild. Psionic is from the Psionics Handbook, and you all know where the half-fiend is from.
Abyssal Guardian (Legendary Wolf + Elder Magical Beast + Multiheaded (2 Extra) + Half-Fiend + Psionic)
Large Magical Beast
Hit Dice: 22d8+198 (297)
Initiative: +10 (+10 Dex)
Speed: 60 Ft, Fly 60 Ft. (Average)
AC: 33 (-1 Size, +10 Dex, +10 Natural, +4 Deflection)
Attacks: 3 Bite +34 melee, 2 Claw +27 Melee
Damage: Bite 2d8+19, Claw 1d6+6
Face/Reach: 5 Ft. By 10ft/5ft
Special Attacks: Trip, Spell-Like Abilities, Psionics
Special Qualities: Scent, Speech, Spellcasting Affinity, Immunities, Darkvision 60’, Power Resistance: 25, Telepathy
Saves: Fort: +29 Ref: +22 Will: +7
Abilities: Str:36, Dex:30, Con:28, Int:18, Wis:14, Cha:17
Skills: Bluff +18, Climb +16, Diplomacy +18, Concentration +22,
Gather Information +18, Heal +17, Hide +10, Intimidate +18,
Knowledge (Geography) +19, Knowledge (History) +19, Knowledge (Nature) +19, Knowledge (Planes) +19, Hide +22, Listen +23, Move Silently +27, Search +17,
Scry +17, Search +12, Spot +23, Swim +16, Wilderness Lore +17*
Feats: Fearsome Bearing#, Flyby Attack, Inertial Barrier&, Mind Whispers#
Climate/Terrain: Any forest, hill, plains, mountains, and Subteranean /Warm Plain, and Subteranean
Organization: Solitary or Pack (Leads 2-5 two-headed half-fiend wolves) or Colony (leads 20-100 fiendish humanoids)
Challenge Rating: 17
Treasure: Twice Standard
Alignment: Always Neutral Evil
Advancement: Does it really need to?
# = From Legends and Lairs: Monster’s Handbook
&= From Psionic’s Handbook
Abyssal guardians are the hounds of hell, created to destroy any who try to steal hells secrets. They were created by greater demons and devils, but no matter what have an extreme dislike of hellhounds and hellcats. Clans of them can be found in the Grey Waste.
Combat
Guardians only attack when necessary. They usually intimidate first, if they must use their power they will however. They tend to start combat with Breath of the Dragon.
Many of their powers are geared more toward dealing with teleporters. This tends to be a nono around them, anyone who teleports is the next target, and if there is an entire pack some will go after the teleporter while the rest stay behind.
Immunities: An abyssal guardian is immune to poison. They also have acid, cold, electricity, and fire resistance 20.
Psionics (Sp): At will – Baleful Teleport, Breath of the Dragon, Divert Teleport, Fission, Iron Body, Planeshift, See Invisibility, Shadow Body, Teleport without Error,
Time Regression, Temporal Velocity, Trace Teleport, Ultrablast. These abilities are as the powers manifested by an 22nd-level psion.
Attack/Defense Modes (Sp): At will – ego whip, id insinuation, Mind Blast, Mind Thrust, Psychic Crush/empty mind, intellect forturess, mental barrier, thought shield, tower of iron will
Spell-Like Abilities: 3/day any three 1st level divine spells as a sorcerer of 5th level.
3/day-Darkness, Poison, Unholy aura; 1/day – Blasphemy, Contagion, Desecreate, Destruction, Horrid Wilting, Summon Monster IX (Fiends Only), Unhallow, Unholy Blight; as a 22nd level sorcerer.
Speech (Ex): 7 languages
Spellcasting Affinity (Ex): An abyssal guardian may use spells unhindered by its physical form.
Telepathy (Su): An abyssal guardian can communicate telepathically with any creature witin 100 feet that has a language.
Trip (Ex): An abyssal guardian that hits with a bite attack can attempt to trip the opponent as a free action (see page 139 in the PHB) without making a touch attack or provoking an attack of opportunity. If the attempt fails, the opponent cannot react to trip the abyssal guardian.
Skills: An abyssal guardian receives a +6 racial bonus to Listen and Spot checks, a +4 racial bonus to Hide and Search checks, and a +2 racial bonus to Move Silently checks. *It also receives a +4 racial bonus to Wilderness Lore checks when tracking by scent.