Beast
Sand Dragon Worm
CR 17
Gargantuan Beast — Unaligned
In the World
The apex megafauna of the Blackglass Wastes. Blind, entirely deaf, navigating entirely by heat and vibration. A Sand Dragon Worm detects footfall at half a mile. It detects Essa activation at twice that range — the heat signature of vial combustion reads to the Worm like prey at a full sprint. An adult reaches sixty feet in length. The scale plates that ring its midsection have partially crystallized around Essa ore deposits in its body, making it the only natural creature on the continent that is itself a source of raw T3–T4 Essa. The Vault-Keepers have standing contracts for intact Worm organs. Nobody has delivered one twice.
Traits
Heat Sense
The Sand Dragon Worm can pinpoint the location of any creature or object generating heat within 60 ft. Essa activations within 300 ft are automatically detected. The Worm has advantage on Perception checks relying on these senses.
Essa Saturation
The Sand Dragon Worm is infused with raw T3 Essa. Any creature that deals fire or force damage to the Worm takes 7 (2d6) force damage as feedback. Additionally, when the Worm dies, every creature within 30 ft must succeed on a DC 18 DEX saving throw or take 35 (10d6) force damage (half on success) as contained Essa vents explosively.
Tunneler
The Sand Dragon Worm can burrow through solid rock at half speed, leaving a tunnel 10 ft in diameter. It can surface or submerge as part of its movement, treating this as difficult terrain for other creatures.
Siege Monster
The Sand Dragon Worm deals double damage to objects and structures.
Actions
Multiattack
The Sand Dragon Worm makes one Bite attack and two Tail Slam attacks, or uses Surface Burst instead of Bite.
Bite
Melee Weapon Attack: +15 to hit, reach 10 ft, one target. Hit: 31 (4d10 + 9) piercing damage. If the target is Large or smaller, it is grappled (escape DC 20). While grappled, the target is restrained. The Worm can only bite one grappled creature at a time.
Swallow
The Worm makes one Bite attack against a Large or smaller creature it is grappling. On a hit, the target is swallowed. A swallowed creature is blinded, restrained, and has total cover. At the start of each of its turns, it takes 21 (6d6) acid damage. If a swallowed creature deals 30 or more damage to the Worm in a single turn from the inside, the Worm must make a CON save (DC 12 + damage dealt) or regurgitate all swallowed creatures.
Tail Slam
Melee Weapon Attack: +15 to hit, reach 15 ft, one target (not currently grappled). Hit: 22 (3d8 + 9) bludgeoning damage. The target must succeed on a DC 22 STR saving throw or be knocked prone.
Surface Burst (Recharge 5–6)
The Worm surges upward through the ground. All creatures in a 20 ft radius around it must succeed on a DC 20 DEX saving throw or take 45 (10d8) bludgeoning damage and be knocked prone (half damage and not knocked prone on success). The Worm then immediately burrows.
Legendary Actions
Detect
The Worm makes a Perception check or uses its Heat Sense.
Tail Slam
The Worm makes one Tail Slam attack.
Essa Discharge (Costs 2)
The Worm releases raw Essa in a 30 ft line. Each creature in the line makes a DC 18 DEX saving throw, taking 28 (8d6) force damage on a failed save, or half on success.