Shale Behemoth

Family: Shale

Gargantuan elemental, unaligned

Armor Class 20 (natural armor)
Hit Points 409 (21d20 + 189)
Speed 40 ft., burrow 40 ft.

STR	DEX	CON	INT	WIS	CHA
30 (+10)	10 (+0)	29 (+9)	3 (-4)	18 (+4)	10 (+0)

Saving Throws Dex +7, Con +16, Wis +11
Skills Stealth +7
Damage Resistances piercing, slashing
Senses darkvision 60 ft., tremorsense 120 ft., passive Perception 14
Languages –
Challenge 23 (50,000 XP)
Proficiency Bonus +7

SPECIAL TRAITS

• Stone Camouflage. The behemoth has advantage on Dexterity (Stealth) checks made to hide in rocky terrain.
• Tunneler. The behemoth can burrow through solid rock at half its burrow speed and leaves a 15-foot-diameter tunnel in its wake.

ACTIONS

• Multiattack. The behemoth makes three claw attacks or hurls three shards. It can replace one attack with Crystal Prison.
• Claw. Melee Weapon Attack: +17 to hit, reach 20 ft., one target. Hit: 36 (4d12 + 10) piercing damage. If the target is a Large or smaller creature, it is grappled (escape DC 20).
• Crystal Prison. Melee Weapon Attack: +17 to hit, reach 20 ft., one target grappled by the behemoth. Hit: 28 (4d8 + 10) piercing damage, and the target is impaled on the behemoth’s jagged carapace until the grapple ends. While impaled, the target moves with the behemoth and takes 19 (3d12) piercing damage at the start of each of the behemoth’s turns.
• Hurl Shard. Ranged Weapon Attack: +17 to hit, range 60/120 ft., one target. Hit: 28 (4d8 + 10) piercing damage. On a hit or miss, a humming shard lands in the target’s space. At the start of the behemoth’s next turn, the shard explodes. Each creature within 20 feet of the shard when it explodes must make a DC 24 Dexterity saving throw, taking 16 (3d10) thunder damage and 16 (3d10) piercing damage on a failed saving throw, or half as much damage on a successful one.
• Screeching Scrape (Recharge 5-6). The behemoth rubs its crystalline joints against the ground or a nearby wall, causing a deafening squeal of mineral on rock. Creatures within 60 feet of the behemoth that can hear the squeal must make a DC 24 Constitution saving throw. On a failure, a creature takes 65 (10d12) thunder damage, is deafened for 24 hours, and is stunned until the end of its next turn. On a success, a creature takes half as much damage and isn’t deafened or stunned.

ABOUT

A shale behemoth’s body is covered in a dragon’s horde worth of rubies, sapphires, emeralds, and other gemstones. Mysteriously, many shale behemoths grow not only mundane minerals and gems on their carapaces, but also alchemical and magical stone items such as thunderstones, elemental gems, and even powerful crystal balls.

In addition to the mundane gems and the magical items that protrude from a shale behemoth’s body, this gentle giant grows a unique form of acoustically sensitive crystal that can generate and amplify deafening sonic signals. A shale behemoth won’t usually go out of its way to attack smaller creatures, but when threatened, the animal can use its resonant crystals to generate bone-shaking shockwaves and eardrum-rupturing reverberations.

The most venerable of all shale spitters are called shale behemoths. These mountainous monstrosities resemble quaking mounds of chitinous plating, sedimentary rock, and mineral formations. Countless crystalline structures and gemstone deposits pock the ancient being’s carapace, creating a constellation of dazzling jewels that range from common quartz to lustrous diamond. Their massive size means shale behemoths confine themselves to only the largest underground caverns. When it must relocate, a behemoth’s lumbering journey shakes the entire mountain in which it dwells.