Cavitation & Crabs
A new spell and a new monster, both inspired by crustaceans.
Cavitation of Bubbles
4th-level evocation
Casting Time: 1 action
Range: 120 feet
Components: V, S, M (a crustacean’s claw)
Duration: Concentration, up to 1 minute
You create a dome of bubbles on a solid surface within range. The dome is a hemisphere with a 20-foot radius and 1-foot thick walls. The multitude of bubbles make the dome opaque to sight, although light does refract through the bubbles.
When the dome appears, each creature within a square through which the bubbles pass must make a Dexterity saving throw. On a failed save, the creature ends up inside dome in the space nearest to its starting space. On a successful save, the creature ends up outside the dome in the space nearest to its starting space.
The dome is an object that can be damaged and thus breached. Each 5-foot section of dome has AC 10 and 3 hit points, and it is vulnerable to piercing damage. Reducing a 5-foot section of dome to 0 hit points destroys that section. Each creature within 10 feet of the destroyed section must make a Constitution saving throw. On a failed save, a creature takes 5d6 thunder damage and is stunned until the end of its next turn. On a successful save, a creature takes half as much damage and is not stunned.
At Higher Levels: When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d8 for each slot level above 4th.
“Crabmen are man-sized intelligent crabs. They walk upright on two pair of legs. The small pincers tipping the short arms above their legs are used for fine manipulation. The two longer arms end in large claws. Two slender eyestalks bob above the beak-like collection of mandibles which makes up the crabman’s mouth. Male crabmen are often brightly colored and females may be reddish-brown, green, or black” Monstrous Manual, page 47. (Nota Bene: That’s an affiliate link.)
Coastal Hunter-Gatherers. Crabmen live in tribal groups in coastal regions. Most of the time, crabmen are peaceful, content to hunt sealife and gather molluscs and aquatic plants for food. Crabmen may raid coastal towns, especially during times when food is scarce or their territories are threatened. Crabmen covet shiny metal, especially silver-colored metal. Crabmen lair in coastal caves and some of the time dig burrows into seaside cliffs. These burrows consist of tunnels radiating from a common chamber, each tunnel leading to a crabman’s lair.
Xenophobes. Crabmen speak only their own language of hisses and clicks. Humanoids lack the anatomy to speak the crabmen’s tongue in anything other than the most rudimentary manner. Even then, crabmen seldom listen. They have little to no desire to communicate or associate with other intelligent creatures.
Predator and Prey. Sahuagin view crabman legs and claws as tasty delicasies. Crabmen in turn hate sahuagin more than any other creature.
Crabman
Medium monstrosity, neutral
Armor Class 14 (natural armor)
Hit Points 32 (5d8+10)
Speed 25 ft., swim 15 ft.
STR 17 (+3), DEX 10 (+0), CON 15 (+2), INT 8 (-1), WIS 11 (+0), CHA 9 (-1)
Skills Survival +2
Senses darkvision 60 ft., passive Perception 10
Languages Crabman
Challenge 1 (200 XP)
Amphibious. The crabman can breathe air and water.
Regrowth. After a long rest, the crabman regrows severed limbs and damaged eyestalks.
Actions
Multiattack. The crabman makes two pincer attacks.
Pincer. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 6 (1d6+3) bludgeoning damage.
Crabman Hunter
Medium monstrosity, neutral
Armor Class 14 (natural armor)
Hit Points 75 (10d8+30)
Speed 25 ft., swim 15 ft.
STR 18 (+4), DEX 10 (+0), CON 16 (+3), INT 10 (+0), WIS 13 (+1), CHA 11 (+0)
Skills Perception +3, Stealth +2, Survival +3
Damage Resistances bludgeoning from nonmagical weapons
Senses darkvision 60 ft., passive Perception 13
Languages Crabman
Challenge 3 (700 XP)
Amphibious. The crabman hunter can breathe air and water.
Keen Sight and Smell. The crabman hunter has advantage on Wisdom (Perception) checks that rely on sight or smell.
Regrowth. After a long rest, the crabman hunter regrows severed limbs and damaged eyestalks.
Actions
Multiattack. The crabman hunter makes two pincer attacks. If the crabman hunter is grappling a creature, the crabman hunter can also use its bite once.
Pincer. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 7 (1d6+4) bludgeoning damage. The target is grappled (escape DC 13) if it is a Medium or smaller creature and the crabman hunter doesn’t have two other creatures grappled.
Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d4+4) bludgeoning damage. If the target is grappled, the crabman hunter attacks with advantage.
Crabman Elder
Large monstrosity, neutral
Armor Class 16 (natural armor)
Hit Points 142 (15d10+60)
Speed 25 ft., swim 15 ft.
STR 20 (+5), DEX 10 (+0), CON 18 (+4), INT 12 (+1), WIS 15 (+2), CHA 13 (+1)
Skills Perception +5, Survival +5
Damage Resistances bludgeoning
Senses blindsight 30 ft., darkvision 60 ft., passive Perception 15
Languages Crabman (may understand one or more other languages)
Challenge 7 (2,900 XP)
Amphibious. The crabman elder can breathe air and water.
Keen Sight and Smell. The crabman elder has advantage on Wisdom (Perception) checks that rely on sight or smell.
Regeneration. The crabman elder regains 10 hit points at the start of its turn if it has at least 1 hit point. After a long rest, the crabman elder regrows severed limbs and damaged eyestalks.
Actions
Multiattack. The crabman elder makes two pincer attacks. If the crabman elder is grappling a creature, the crabman elder can also use its bite once.
Pincer. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 12 (2d6+5) bludgeoning damage. The target is grappled (escape DC 15) if it is a Large or smaller creature and the crabman elder doesn’t have two other creatures grappled.
Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 10 (2d4+5) bludgeoning damage. If the target is grappled, the crabman elder attacks with advantage.
