This immense mound of black slime thunders forward, eyes and mouths and even stranger things forming in its heaving bulk.
Shoggoth CR 19
AC 33, touch 15, flat-footed 26 (+7 Dex, +18 natural, –2 size)
hp 333 (23d8+230); fast healing 10
Fort +19, Ref +14, Will +15
DR 10/—; Immune blindness, charm effects, cold, deafness, ooze traits, sonic; Resist acid 20, electricity 20, fire 20; SR 30
Speed 50 ft., climb 30 ft., swim 50 ft.
Melee 4 slams +30 (3d6+15/19–20 plus grab)
Space 15 ft.; Reach 30 ft.
Special Attacks constrict (3d6+15), maddening cacophony, engulf (4d6+22 bludgeoning damage plus 8d6 acid damage, AC 19, hp 33), trample (4d8+15, DC 36)
Str 40, Dex 24, Con 31, Int 5, Wis 22, Cha 13
Base Atk +17; CMB +34 (+39 grapple); CMD 51 (cannot be tripped)
Environment cold aquatic or underground
Organization solitary or tide (2–6)
All-Around Vision (Ex) A shoggoth's many sense organs grant a +4 racial bonus on Perception and immunity to flanking.
Maddening Cacophony (Su) As a free action, a shoggoth can give voice to sounds and words sane life was not meant to hear. All creatures in a 60-foot radius must make a DC 22 Will save or be confused for 1d6 rounds. Each round a creature is affected it takes 1d6 points of Wisdom damage. A creature that saves cannot be affected by this shoggoth's maddening cacophony for 24 hours. This is a sonic mind-affecting effect. The save DC is Charisma-based.
Engulf (Ex) To use this ability, the shoggoth must begin its turn grappling a creature or must trample. A shoggoth may attempt to engulf as many creatures as it grapples or tramples in a round. This ability otherwise functions as swallow whole, save that a creature that cut its way out of a shoggoth leaves no hole in the protoplasmic creature's body.
Although even lunatics and doom-saying prophets desperately claim the monstrous shoggoth is nothing more than a drug-induced vision or thankfully unreal nightmare, the truth is altogether more dire. The shoggoths exist, although they keep to the deepest of ocean trenches or the most remote of forgotten caverns and ruins, emerging only rarely to spread madness and destruction in their slime-caked wakes.
The first shoggoths were created in eons past, long before the first gods turned their attentions to the Material Plane. Some hold that the aboleths engineered them, while certain strange texts hint of a race even older that engineered the first shoggoths as slaves. Eventually, these dread beasts developed enough intelligence to rebel against their creators, and now they lurk, patient but potent, in the lightless deep.