rare cn huge aberration amphibious 

Perception +34; darkvision, scent (imprecise) 60 feet, tremorsense (imprecise) 60 feet

Languages Aklo

Skills Athletics +36, Intimidation +29

Str +10 Dex +6 Con +9 Int -3 Wis +6 Cha +1

AC  39; all-around vision; Fort +33, Ref +30, Will +30; +1 status to all saves vs. magic

HP 275, fast healing 20; Immunities precision, blinded, controlled, critical hits, deafened, sleep; Resistances acid 20, cold 20, sonic 20

Maddening Cacophony (auditory, aura, incapacitation, mental) 60 feet. A shoggoth constantly voices syllables and mutterings that mortals were not meant to hear. A creature entering the aura or starting its turn in the aura must succeed at a DC 38 Will save or become confused for 1 round (2d4 rounds on a critical failure). A creature that successfully saves is temporarily immune for 24 hours.

Speed 40 feet, climb 25 feet, swim 50 feet

Melee [>] pseudopod +35 (magical, reach 30 feet), Damage 4d10+18 bludgeoning plus Grab

Constrict [>] 2d10+15 bludgeoning.

Eat Away A creature that begins its turn inside the shoggoth takes 9d6 acid damage.

Engulf [>>] DC 40, 6d6 acid, Escape DC 40, Rupture 40.

Bestiary, page 293.