This man-sized creature seems little more than an accumulation of vaguely insectoid limbs, joints, and claws with a number of yellow eyes peeking through the folds in its dull, knobby flesh.
XP 1,200
NE Medium aberration
Init +6; Senses darkvision 60 ft.; Perception +12
AC 16, touch 12, flat-footed 14 (+2 Dex, +4 natural)
hp 44 (8d8+8)
Fort +5, Ref +4, Will +7
DR 5/slashing; Defensive Ability compartmentalized form
Speed 30 ft.
Melee 4 claws +7 (1d4+1)
Space 5 ft.; Reach 5 ft.
Special Attacks implant gnarlomite
Str 13, Dex 14, Con 13, Int 10, Wis 13, Cha 8
Base Atk +6; CMB +7; CMD 19
Feats Combat Reflexes, Great Fortitude, Improved Initiative, Weapon Focus (claw)
Skills Acrobatics +13, Climb +12, Perception +12, Stealth +13
Languages Undercommon
Environment any
Organization solitary, pair, gang (3–6)
Treasure standard
Compartmentalized Form (Ex) When a gnarlomorph takes slashing damage greater than one-fifth its full normal hit points (8 for a normal gnarlomorph), part of its semi-amorphous body is severed off and becomes a gnarlomite (detailed below). The gnarlomorph has no direct control over its gnarlomites, but they will generally act at its direction. In addition, when the gnarlomorph is killed, 1d4 gnarlomites are created in the square it occupied.
Implant Gnarlomite (Ex) Once per round, when a gnarlomorph deals damage to a living creature with its claw attack, it can choose to implant an autonomous clump of its own flesh, known as a gnarlomite, into the wound. When making this attack, the gnarlomorph takes damage equal to one-tenth its full normal hit points (4 for a normal gnarlomorph). A new gnarlomite is created and immediately performs a grapple check against the target. If the grapple check fails, the gnarlomite lands at the target’s feet in its square.

This lump of flesh is no larger than a human forearm and appears similar to the severed limb of some alien insect. It moves on several thin legs, its form slicked in a strange grease.
XP 100
NE Tiny aberration
Init +5; Senses darkvision 60 ft.; Perception +5
AC 17, touch 17, flat-footed 12 (+2 size, +5 Dex)
hp 4 (1d8–1)
Fort –1, Ref +5, Will +3
Defensive Ability skitter
Speed 20 ft.
Melee claw +5 (1d4–1 plus 1d6 acid plus grab)
Space 2-1/2 ft.; Reach 0 ft.
Str 4, Dex 20, Con 8, Int 10, Wis 13, Cha 8
Base Atk +0; CMB +3 (+7 grapple); CMD 10
Feats Agile Maneuvers, Weapon Finesse^b
Skills Acrobatics +9, Climb +5, Perception +5, Stealth +11; Racial Modifiers +4 Climb
Languages —
Environment any
Organization clutch (3–6) or swarm (7–14)
Treasure none
Acid (Ex) The gnarlomorph secretes a strange substance that helps it burrow into its foe’s flesh and bond with its tissue. This substance adds 1d6 acid damage to the gnarlomite’s claw attack.
Attach (Ex) When a gnarlomite damages a living creature with its claw attack in a grapple, it inserts sinuous tendrils into the creature and begins to incorporate itself into the target’s flesh. This deals 1d3 Charisma damage to the target. If the target is reduced to 0 Charisma by this attack, it falls unconscious, becoming a gnarlomorph with the young simple template over the course of the next 1d4 rounds. Killing the gnarlomite before this time elapses stops the transformation. A remove disease spell cast on the target adds 5 rounds to the transformation.
Grab (Ex) Gnarlomites may grab creatures of any size.
Skitter (Ex) Gnarlomites are quick on their feet (or whatever pass for their feet), and gain a +5 dodge bonus to AC against attacks of opportunity as long as their movement is unimpeded (such as by difficult terrain or a grease spell).

Gnarlomorphs are inscrutable creatures whose only goal seems to be to kill other living beings for food and for their gruesome form of reproduction. Certainly they are intelligent, though, as proven by their occasional willingness to speak to their victims, so its stands to reason that their goals could be less primal.

Knowledge (Dungeoneering) DC 15 This horror is a gnarlomorph, a segmented abomination known for the ability of its body parts to continue acting autonomously even after being severed from the whole. These autonomous parts are known as gnarlomites, and the gnarlomorph reproduces by planting a gnarlomite in a living creature. This result also reveals the gnarlomorph's damage reduction.
Knowledge (Dungeoneering) DC 20 To avoid being swarmed by gnarlomites, it is best to avoid using slashing weapons against a gnarlomorph.