Tenebrius Grue

Armor Class 17 (natural armor)

Hit Points 126 (11d10 + 66)

Speed 40 ft., burrow 40 ft.

STR

20 (+5)

DEX

10 (+0)

CON

22 (+6)

INT

9 (-1)

WIS

16 (+3)

CHA

11 (+0)

Saving Throws STR +9, CHA +4

Skills +6, +3

Damage Vulnerabilities Thunder

Damage Resistances Piercing and Slashing from Nonmagical Attacks that aren't Adamantine

Damage Immunities Poison

Condition Immunities , , , ,

Senses 120 ft., Passive Perception 19

Languages Terran

Challenge 9 (5,000 XP)

Proficiency Bonus +4

Earth Glide. The grue can burrow through nonmagical, unworked earth and stone. While doing so, the grue can choose whether or not to disturb the material it moves through.

Stone Camouflage. The grue has advantage on Dexterity (Stealth) checks made to hide in underground or rocky terrain.

Magic Aversion. The grue is capable of sensing active magical effects within 120 feet of it. These include spells, magical abilities, and certain powerful magical items (at the GMs discretion). They also are more able to resist the power of magic and have advantage on saving throws against spells and spell-like abilities.

Actions

Multiattack. The grue makes three claw attacks and one tentacle or bite attack.

Claw. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 9 (1d8 + 5) slashing damage.

Tentacle. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit: 9 (1d12 + 5) bludgeoning damage. A creature hit by a tentacle attack must succeed on a DC 17 Strength saving throw or become restrained by the grue.

Bite. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 22 (5d6 + 5) piercing damage. Creatures restrained by the grue take an additional 12 (5d6 + 5) piercing damage

Burrowing Burst. If the grue burrows at least 15 feet as part of its movement, it can then use this action to burst from the ground in a space that contains one or more other creatures. Each of those creatures is thrown up to 15 feet out of the space the grue is now occupying. Affected creatures take 14 (3d6 + 4) bludgeoning damage plus 14 (3d6 + 4) slashing damage and must succeed on a DC 17 Strength or Dexterity saving throw (target's choice) or be knocked prone. On a successful save, the creature takes only half the damage, isn't knocked prone, and is pushed 5 feet out of the grue's space into an unoccupied space of the creature's choice. If no unoccupied space is within range, the creature instead falls prone in the bulette's space.

Stone Breath (Recharge 5–6). The grue exhales a blast of stone and earth in a 30-foot cone. Each creature in the cone must make a DC 17 Strength saving throw. On a failed save, the creature takes 27 (6d8) bludgeoning damage and is knocked prone. On a successful save, the creature takes half as much damage, and remains standing.

Description

The Tenebrius Grue's rocky skin is thick, rugged, and segmented, resembling the outer layer of a crustacean. It's mottled with varying shades of gray and black, allowing it to camouflage seamlessly with the rock and shadows of the subterranean environment. Its luminescent veins have evolved to form intricate patterns across its exoskeleton, glowing dimly with a cold, blue light.

The creature's head is a formidable sight, armored heavily with chitinous plates. It lacks eyes but has a vast, horizontal slit for a mouth, which grinds open and shut with rows of serrated, crystalline teeth. These teeth are designed not just for eating, but also for burrowing through rock and earth, acting as a biological drill. Flanking the mouth are specialized sensory organs that can detect vibrations in the ground, aiding in navigation and prey detection.

The Tenebrius Grue boasts eight powerful limbs, each ending in a shovel-like hand with razor-sharp claws. These claws are constructed of a mineral-infused chitin, allowing them to scrape and burrow through the hardest stone. Each limb's joint hosts an array of smaller tendrils, used for finer manipulation and sensing its environment.

From its back sprout larger, muscular tendrils, each tipped with a rock-hard spike. When burrowing, these tendrils trail behind, acting as anchors or propelling it forward with strong thrusts. During combat, they become whip-like weapons or tools to ensnare and pull prey closer.

This behemoth earthen creature stands at an imposing 12 feet tall when fully upright, though it often adopts a more sprawling stance when burrowing or hunting. Its body spans about 15 feet in length, with tendrils that can extend an additional 8 feet.

The Tenebrius Grue is a master burrower, creating vast networks of tunnels as it hunts and seeks out mineral-rich veins to consume. Its burrowing often leaves behind smooth, glass-like tunnels in its wake, as the intense friction and heat from its mouth and claws melt and vitrify the surrounding rock. It is both a predator and a mineral scavenger, deriving sustenance from the rock itself and any unfortunate creature that becomes its prey.

When hunting, the Grue relies on its acute sense of vibration, lying in wait and feeling for the footsteps of creatures above or nearby. Once it detects prey, it can burst forth from the rock walls or ground with terrifying speed, using both its powerful limbs and tendrils to ensnare its target.

Due to its size and the nature of its hunting technique, the Tenebrius Grue often leaves behind vast open caverns or sinkholes at the surface, making its presence a known danger in regions it's rumored to inhabit.