Shale Swarm

Family: Shale

Large swarm of Small elementals, unaligned

Armor Class 16 (natural armor)
Hit Points 37 (5d10 + 10)
Speed 25 ft., burrow 25 ft., climb 25 ft.

STR	DEX	CON	INT	WIS	CHA
17 (+3)	12 (+1)	14 (+2)	3 (-4)	12 (+1)	7 (-2)

Damage Resistances bludgeoning, piercing, slashing
Condition Immunities charmed, frightened, grappled, paralyzed, petrified, prone, restrained, stunned
Senses darkvision 60 ft., tremorsense 60 ft., passive Perception 11
Languages –
Challenge 2 (450 XP)
Proficiency Bonus +2

SPECIAL TRAITS

• Churning Wake. The swarm leaves behind a trail of furrowed earth and scree as it burrows through the earth. After the swarm burrows, any spaces above the swarm’s path (including open spaces such as a cavern floor) become difficult terrain.
• Rock Stride. The swarm ignores difficult terrain in caves and rocky areas.
• Swarm. The swarm can occupy another creature’s space and vice versa, and the swarm can move through any opening large enough for a Small, newly hatched shale splitter. The swarm can’t regain hit points or gain temporary hit points.

ACTIONS

• Bite. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 13 (3d6 + 3) piercing damage, or 6 (1d6 + 3) piercing damage if the swarm has half of its hit points or fewer.
• Cloud Cover. Each shale spitter in the swarm rapidly gnaws on nearby rock material and kicks apart clods of loose dirt, causing a dust cloud to form in the swarm’s space. The area is heavily obscured. The dust cloud lasts for 1 minute or until it is dispersed by a strong wind.

ABOUT

When the time is right, shale spitters lay clutches of pebble-like eggs in the walls of their burrows. Shale spitter clutches-also called shale swarms or “compactions” tend to emerge from their eggs all at once. Newly hatched, shale spitters are less dangerous than common voles, and so they must rely on their compaction’s sheer numbers for safety. Only a few shale spitters out of a hundred survive to adulthood.

Shale swarms are as adept at rooting through rock as scuttling atop it. The activity of so many little chomping mouths means that shale swarms leave trails of churned stone and rock dust behind them, much like woodlice leave trails of sawdust as they wind through tree trunks.

Unwary miners can run into trouble if they disturb hidden shale spitter burrows. To say nothing of the biting, clawing swarm of isopods as individual menaces, an upset shale swarm constitutes a deadly hazard to all around it when the compaction gets to tumbling down steep mountainsides and rocky gulches. Entire caravans, mining camps, and mountain villages have been reduced to rubble as a result of so-called shale swarm avalanches.