uncommon ce large aberration 

Perception +18; darkvision

Languages Abyssal, Aklo, Common, Draconic, Protean, Undercommon; telepathy 100 feet

Skills Acrobatics +17, Arcana +18, Athletics +16, Lore (all subcategories) +18, Occultism +21, Stealth +17

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

AC  26; Fort +15, Ref +13, Will +18; +1 status to all saves vs. magic

HP 140; Immunities confused; Weaknesses brain loss

Brain Blisters A brain collector has seven brain blisters on its back that it uses to house stolen brains. A brain collector without all seven blisters full is stupefied with a value equal to the number of empty blisters.

Brain Loss If a brain collector takes 30 damage from a critical hit or takes 25 mental damage, it must succeed at a DC 26 save (Fortitude for critical damage or Will for mental damage) or one of its brain blisters is destroyed.

Speed 25 feet, fly 30 feet

Melee [>] jaws +20, Damage 2d12+6 piercing plus brain collector venom

Melee [>] claw +20 (agile), Damage 2d8+6 slashing

Occult Spontaneous Spells DC 26, attack +18; 4th (2 slots) confusion, phantasmal killer; 3rd (3 slots) dispel magic, haste, paralyze; 2nd (4 slots) humanoid form, invisibility, mirror image, paranoia; 1st (4 slots) mindlink, ray of enfeeblement, true strike, unseen servant; Cantrips (4th) dancing lights, detect magic, mage hand, prestidigitation

Brain Collector Venom (poison) Saving Throw DC 26 Fortitude; Maximum Duration 6 rounds; Stage 1 1d6 poison and enfeebled 1 (1 round); Stage 2 1d6 poison, enfeebled 1, and slowed 1 (1 round); Stage 3 2d6 poison, enfeebled 2, and slowed 1 (1 round)

Collect Brain [>] (manipulate) The brain collector collects a brain of a creature that has been dead for no more than 1 minute. It can then use an Interact action to secure the brain in one of its empty brain blisters.

Bestiary, page 46.