Astral Dreadnought (CR 17)

Gargantuan Outsider
Alignment: Always neutral
Initiative: +2 (-2 Dex, +4 Improved Initiative); Senses: Spot +23

AC: 20 (-4 size, -2 Dex, +16 natural), touch 4, flat-footed 20
Hit Dice: 18d8+234 (315 hp)
Fort +24, Ref +8, Will +13
Speed: Fly 180 ft. (poor)
Space: 20 ft./15 ft.
Base Attack +18; Grapple +27
Attack: 2 claws +30 melee, bite +28 melee
Full Attack: 2 claws +30 melee, bite +28 melee
Damage: Claw 2d6+16, bite 2d8+8
Special Attacks/Actions: Sever silver cord, improved grab, swallow whole, rend 4d6+24
Abilities: Str 42, Dex 7, Con 37, Int 3, Wis 14, Cha 18
Special Qualities: SR 28, antimagic cone, frightful presence
Feats: Improved Critical (bite); Improved Critical (claw); Improved Initiative; Multiattack; Power Attack; Improved Sunder; Improved Bull Rush; Track
Skills: Hide +7, Move Silently +19, Spot +23, and Survival +23
Advancement: 19-32 HD (Gargantuan); 33-54 HD (Colossal)
Climate/Terrain: Any land and underground
Organization: Solitary
Treasure/Possessions: None

Source: Manual of the Planes

Sever Silver Cord (Ex): If the astral dreadnought can attack an astral traveler's back (by flanking it, catching it flat-footed, or pursuing it while panicked and fleeing), it can attack the silver cord that connects the astral form to its material counterpart. The normally insubstantial cord is treated as a tangible object with the owner's AC, hardness 10, and 20 hit points (see Attack an Object in Chapter 8 of the Player's Handbook). A silver cord visibly trails 5 feet behind an astral traveler before fading into the astral medium. Attacking it draws an attack of opportunity from the astral traveler.

When the cord is damaged, the astral traveler must succeed at a Fortitude save (DC 13) or be immediately forced to return to its body. Severing the silver cord destroys both the astral form and the body on the Material Plane.

Improved Grab (Ex): To use this ability, the astral dreadnought must hit with its bite attack. If it gets a hold, it automatically deals bite damage and can try to swallow the opponent.

An astral dreadnought that hits with a claw attack grabs as above. If it gets a hold, it picks up the opponent and transfers it to the mouth as a partial action, automatically dealing bite damage as above.

Swallow Whole (Ex): The round after it grabs an opponent, an astral dreadnought can try to swallow it by making a successful grapple check. Once inside, the opponent takes 2d8+16 points of crushing damage plus 2d8 points of acid damage every round. A swallowed creature can crawl out of the gullet by making a successful grapple check. This returns it to the astral dreadnought's maw, where another successful grapple check is needed to get free. A swallowed creature can also cut its way out by using claws or a Sma7ll or Tiny slashing weapon to deal 35 points of damage to the gullet (AC 24). Once the creature exits, muscular action closes the hole; another swallowed creature must cut its own way out.

The astral dreadnought's gullet can hold two Huge, four Large, eight Medium-size, sixteen Small, or thirty-two Tiny or smaller opponents.

Rend (Ex): If an astral dreadnought hits with both claw attacks, it latches onto the opponent's body and tears the flesh. This attack automatically deals an additional 4d6+24 points of damage.

Antimagic Cone (Su): An astral dreadnought's single eye continually produces 150-foot antimagic cone extending straight ahead from the creature's front. This functions just like antimagic field cast by an 18th-level sorcerer, with exception noted below. Once each round, during its turn, the astral dreadnought decides which way its eye faces. The astral dreadnought can only make bite attacks against creatures to its front.

All magical, spell-like, and supernatural effects within the cone are suppressed, except for those that brought the subjects to the Astral Plane in the first place (the astral projection spell, for example). Those effects are locked in place while the subjects are in the cone and cannot be dismissed, trapping the subjects on the Astral Plane while under its effect.

Frightful Presence (Ex): The mere sight of an astral dreadnought can unsettle or even panic opponents. The ability takes effect automatically whenever the astral dreadnought attacks or moves within 200 feet of a foe. Those within range must succeed at a Will save (DC 23) or be affected. Creatures with 4 HD or fewer become panicked for 4d6 rounds, and those with 5 HD or more become shaken for 4d6 rounds. Those who succeed at the Will save are immune to the astral dreadnought's frightful presence for one day.