Neh-Thalggu, Lesser

This horrific creature looks like a gigantic, deformed head walking on six crab-like legs. Above its eyes, five waving tentacles protrude from between a dozen melon-sized lumps.

Neh-Thalggu, Lesser CR 8
XP 4,800
NE Large aberration (extraplanar)
Init +5; Senses darkvision 60 ft.; Perception +15
Defense
AC 21, touch 16, flat-footed 20 (+1 Dex, +1 dodge, +5 insight, +5 natural, -1 size)
hp 75 (10d8+30)
Fort +6, Ref +4, Will +9
DR 10/magic; Immune critical hits, death from massive damage, sneak attacks, coup de grace; SR 19
Offense
Speed 50 ft. or via dimension door
Melee bite +9 (1d10+3 plus poison), 5 head-tentacles +4 touch (1d6+1)
Space 10 ft.; Reach 5 ft.
Special Attacks spells
Statistics
Str 17, Dex 13, Con 16, Int 14, Wis 14, Cha 17
Base Atk +7; CMB +11; CMD 22 (30 vs. trip)
Feats Blind-Fight, Dodge, Eschew Materials, Improved Initative, Power Attack
Skills Knowledge (arcana) +12, Knowledge (planes) +15, Perception +15, Sense Motive +12, Spellcraft +15, Stealth +14
Languages Neh-Thalggu (sign language "spoken" with head-tentacles), telepathy 100 ft.
SQ amorphous physiology, dimensional travel
Ecology
Environment any
Organization solitary
Treasure triple standard
Special Abilities
Poison (Ex): Bite-injury; save Fort DC 18, frequency 1/round for 6 rounds, effect 1d3 Con, cure 2 saves.
Head-Tentacles (Ex): The long, whiplike tentacles that frame either side of a brain collector’s face can deliver a dangerous touch attack that, if successful, causes the target to dehydrate and wither (1d6 points of desiccation Damage). It can bring all five tentacles to bear on a single target facing it or divide its attacks against up to five targets that it threatens.
Extract Brains (Ex): After killing a humanoid creature, a lesser brain collector carefully opens the victim's head and removes the brain, lodging in an unused storage sac above and behind its eyes.
A brain collector prefers to absorb brains of high-level arcane spellcasters but is fully capable of extracting those of other foes as a highly effective attack. When encountered, assume a lesser neh-thalggu has a full retinue of twelve stolen brains. Each brain less than the full twelve bestows one negative level on the neh-thalggu (though these never convert to actual level loss), which is a powerful incentive for the creature to always keep its brain-sacs filled. A neh-thalggu is free to draw on all the Knowledge skills of each brain it currently stores, using the base ranks in a skill possessed by each brain, and adjusted by the neh-thalggu’s own skill modifiers for the Knowledge skill in question (or its Intelligence modifier, for a skill it has no ranks in).
A creature whose brain has been harvested by a brain collector cannot be raised, reincarnated, or resurrected while the brain is in the creature, because the collector preserves and draws upon the soul and basic personality of the creature for as long as it retains the brain.
Dimensional Travel (Sp): A brain collector’s preferred method of locomotion is via dimension door, which it can do as a swift action. It can also use teleport without error or plane shift at will as a move-equivalent action.
Spells: A fully stocked brain collector can cast arcane spells as a 12th-level sorcerer (one level of spell-casting ability per brain).
Amorphous Physiology (Ex): A brain collector does not have fixed organs. As such, it is immune to critical hits, death from massive Damage, sneak attacks, and coup de grace.

The Lesser Neh-Thalggu is, as the name suggests, a smaller, less powerful version of the creature commonly referred to as the Brain Collector. However, it is only referred to as "Lesser" by non-Neh-Thalggu. In the very rare instances when more than one variety of Brain Collector have been encountered together, the Neh-Thalggu have made no distinction -- nor seemed to even notice a difference between -- the two types.
Material Plane scolars have never been able to figure out why this is, but there are several possibilities, some of which are explored below. (GMs are encouraged to choose the explanation that best fits their campaign.)
Brain Collectors, like dragons, continue to grow and increase in power as they age. However, Neh-Thalggu society is more of a meritocracy, where those who prove themselves competent are given duties and respect, no matter their physical age.
The two varieties are different subraces, and mature adults of both varieties hold equal station.
Some Neh-Thalggu just stop developing at a certain point, for reasons not even they understand. The Brain Collectors, however, are more concerned with magical prowess, which both types are approximately equal at.
The stat blocks given do not represent the Neh-Thalggu's true form, but the form they take when projecting themselves into the Material Plane. The epic version is an "incomplete" projection; it remains mostly incorporeal, but retains more of the being's mental prowess. The lesser version is a more "complete" projection, which loses more of the original's mental abilities, but achieves full material form, including being able to manipulate solid objects. The two levels of projection may not even be thought of as perfect or imperfect, but just as two different options with their own advantages and disadvantages.