Crabberation

Watchful Stalks. The many seeing eyestalks watch closely and carefully from the creature, the Crabberation is always awake and cannot be surprised.

Amphibious. The Crabberation can breathe on land and underwater.

Made of Crabs. The Crabberation can walk through creatures as the crabs it's made of scuttle around them then reform into the main body.

Craboflage. The Crabberation if staying still unmoving for 1 minute will have it's hive mind of crabs move and position themselves to become invisible or to look like false pieces of environment. (Example, it it lays on grassy land it could take the appearance of a grassy mound, or shuffling crab pigmentation to make natural invisibility)

Colony. anytime the Crabberation suffers 5 or more damage from any source, it projectiles out 1 colony crab up to 20 ft. from itself.

Uncanny mimicry. If the Crabberation listens to speech for a minute, it can speak the spoken language in a clicking mimicry of the language. It will keep the language known until hearing another language that's different forgetting the previous.

Multiattack: The Crabberation can make 2 claw attacks and 1 Bite attack or 3 Crab Beam attacks with tendrils from it's body.

Claw.  Melee weapon attack: +6 to hit, reach 10ft., one creature, hit: (1d12+5) bludgeoning damage. If hit, the target is grappled and must succeed a strength (16) to escape. The Crabberation has 2 claws each of which can grapple 1 creature.

Bite.  Melee weapon attack: +6 to hit, reach 5ft., one creature, hit: (2d8+5) magical piercing damage.

Crab beam. Ranged weapon attack: +5 to hit, reach 60/120ft., one creature, hit: (1d8+5) magic damage. If hit, the creature must succeed a constitution (13) saving throw or be blinded until the start of the Crabberation's next turn.

Tendril. Melee weapon attack: +6 to hit, reach 5ft., one creature, hit: (1d8+5) magical piercing damage. If the creature targeted is dead, then it is filled to the brim with colony crab eggs.

Crab-tillery strike (3 turn CD). The top of the Crabberation sprouts a large hole that fires off a large ball of colony crabs to a location up to 60ft. in a 20ft. radius. It summons 6 colony crabs in the location and creatures in the area must succeed a dexterity (15) saving throw or suffer (6d6) bludgeoning damage or half on a success.