uncommon le huge aberration aquatic 

Perception +17; darkvision

Languages Aklo, Lomos, Aquan, Common, Undercommon

Skills Athletics +16, Deception +15, Intimidation +15, Lore (any one subcategory) +14, Occultism +16

Str +5 Dex +1 Con +6 Int +3 Wis +5 Cha +4

Mucus Cloud (aura, disease) 5 feet. While underwater, an aboleth exudes a cloud of transparent slime. An air-breathing creature adjacent to an aboleth must succeed at a DC 25 Fortitude save each round or lose the ability to breathe air but gain the ability to breathe water for 3 hours.

AC  23; Fort +15, Ref +10, Will +16

HP 135

Speed 10 feet, swim 60 feet

Melee [>] tentacle +16 (agile, magical, reach 15 feet), Damage 2d8+10 bludgeoning plus slime

Occult Innate Spells DC 25; 7th project image (at will), veil (at will); 6th dominate (×3), illusory scene (at will); 5th illusory object (at will); 4th hallucinatory terrain (at will); 3rd hypnotic pattern (at will)

Slime (curse, occult, virulent) A remove disease spell can counteract this curse, but immunity to disease offers no protection against it. Saving Throw DC 25 Fortitude; Stage 1 no ill effect (1 round); Stage 2 the victim's skin softens, inflicting drained 1 (1 round); Stage 3 the victim's skin transforms into a clear, slimy membrane, inflicting drained 2 until the curse ends; every hour this membrane remains dry, the creature's drained condition increases by 1 (permanent)

Bestiary, page 14.