Wall Beast

Wall Hand. The wall beast primarily attacks with one of its two hands, reaching through a wall. When it reaches 0 hit points, it must forcibly withdraw its destroyed arm through the wall or risk losing the arm. The wall beast's hit points represent each of its two hands, and it dies when it loses both of them. If the wall beast is discovered through the crack that its hand emerged from, it will attack in its Revealed form, using the hit points and attacks of its remaining hand (if any).

Revealed Form. If the wall beast is fought from within its hiding hole, it gains access to additional attacks, and loses its bonuses to cover (-5 to AC and Dexterity saving throws).

Grasping Claw. Melee Weapon Attack: +6 to hit, reach 15 ft., one target. Hit: (2d6 + 3) slashing damage. If the target is a Large or smaller creature, it is grappled (escape DC 14). Until this grapple ends, the target is restrained and the wall beast (if not in its revealed form) can only the attack the grappled creature with its crushing grip. If the wall beast takes 20 or more damage in a round, it must forcibly drop all creatures it is grappling.

Crushing Grip. One target grappled by the wall beast takes (3d4 + 3) bludgeoning damage, and must succeed on a Constitution saving throw with a DC equal to 5 + the damage taken or begin suffocating.

Bite (Revealed Form Only). Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: (1d8 + 3) slashing damage.

Retrieving Claw. The wall beast targets one incapacitated creature that is grappled by it. It attempts to pull it through the gap from which its arm emerges, forcibly squeezing the creature. The grappled creatures takes 3d6 bludgeoning damage, and if the target is a Medium-sized creature or smaller, it is pulled through the gap. If the target is a Large-sized creature, then the target is released from the grapple.

Retract Hand. The wall beast retracts its hand through the crevice it emerged from, ignoring all attacks of opportunity.