Sources
CR
Type
Size
Alignment
Movement

Hulking Crab

Huge Beast, Unaligned

Armor Class 17 (natural armor)
Hit Points 76 (8d12 + 24)
Speed 20 ft., swim 30 ft.
STR
19
+4
DEX
8
-1
CON
16
+3
INT
3
-4
WIS
11
+0
CHA
3
-4
Skills Stealth +2
Senses blindsight 30 ft., passive Perception 10
Languages
Challenge 5 (1,800 XP)

Traits

Amphibious. The crab can breathe air and water.

Shell Camouflage. While the crab remains motionless with its eyestalks and pincers tucked close to its body, it resembles a natural formation or a pile of detritus. A creature within 30 feet of it can discern its true nature with a successful DC 15 Intelligence (Nature) check.

Actions

Multiattack. The crab makes two attacks with its claws.

Claw. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit:20 (3d10 + 4) bludgeoning damage, and the target is grappled (escape DC 15). The crab has two claws, each of which can grapple only one target

Lore

Much bigger than a giant crab, a hulking crab has a body 15 to 20 feet in diameter. Its shell is often covered with coral, anemones, ship wreckage, or some other sort of detritus salvaged from the ocean floor.