This maggotlike creature has a long tail covered with frightening hooked suckers.
Grimslake CR 6
CE Large aberration (extraplanar)
Init +5; Senses darkvision 60 ft., tremorsense 30 ft.; Perception +13
AC 19, touch 10, flat-footed 18 (+1 Dex, +9 natural, -1 size)
hp 68 (8d8+32); fast healing 5
Fort +6, Ref +5, Will +10
Defensive Abilities slashing scales; Immune disease; Resist acid 10, fire 10
Speed 20 ft., burrow 20 ft., climb 20 ft.
Melee bite +12 (2d6+7 plus grab), sting +12 (1d6+7 plus grab)
Space 10 ft.; Reach 10 ft.
Special Attacks constrict (1d6+6), marrow drain, penetrating jaws
Spell-Like Abilities (CL 6th; concentration +6)
1/day—slow (DC 13)
Str 24, Dex 13, Con 19, Int 6, Wis 14, Cha 11
Base Atk +6; CMB +14 (+18 grapple); CMD 25 (can't be tripped)
Skills Climb +26, Perception +13
Organization solitary, pair, or tangle (3-10)
Marrow Drain (Ex) A grimslake's tail is covered with suckers that extend long, thin, razor-sharp tendrils to drill into its victim's bones, draining them of marrow. As a swift action, a grimslake can drain marrow from a creature it is grappling or from a helpless creature. The victim can resist this painful attack with a successful DC 18 Fortitude save; otherwise, the creature becomes staggered from the horrific agony for 1 round and takes 1 point of Constitution drain. The save DC is Constitution-based.
Penetrating Jaws (Su) A grimslake's bite attack penetrates cold iron and silver damage reduction.
Slashing Scales (Ex) The scales running in a line down a grimslake's back have razor-sharp ridges and spines, and the creature is adept atlashing at attackers with these scales. Any creature that attacks a grimslake with a natural weapon, unarmed strike, or light weapon must succeed at a DC 15 Reflex save or take 1d4 points of slashing damage. The save DC is Dexterity-based.
The grublike grimslake is commonly found on Abyssal battlefields, where it crawls among the bodies, sucking away marrow and other vital tissues found within the dead. Of course, when fresh carcasses aren't available, grimslakes eagerly to turn to living victims—they take particular delight in the sound of screams as they feed. While on the Abyss, they often hunt lesser demons, but these semi-intelligent scavengers find mortal humanoids a particular delicacy.
The hermaphroditic grimslakes use the remnants of their meals as incubators for their eggs. After eating, they fill the drained bodies with their eggs and fertilize them. Then they abandon the eggs to search for new feeding grounds, leaving behind a hideous legacy. Other scavengers instinctively avoid the egg-filled bodies, and 10 to 12 days later, the corpses burst open, releasing a mass of grimslakes the length of a human arm. These creatures fall upon each other in a ravenous orgy of cannibalism, growing quickly as they consume their kin until, a few days later, the few surviving, fully grown grimslakes go off in search of new food and incubators.
In the Abyss, some demon lords use grimslakes to dispose of bodies. Others use them as implements of torture. The worst keep them as food sources—not to eat the grown specimens, but to dine on corpses pregnant with the grimslakes' seething young.