Assimilated Monk

Control Cord. An Assimilated Monk has a fleshy cord extending from their back that ascends to the roof of the room they inhabit. When they are brought to 0 Hit Points, instead of dying, they become incapacitated. This effect ends after 3 rounds, where they will restore to half of their maximum hit points. 

A creature can choose to attack this cord while the Assimilated Monk is at 0 Hit Points (AC: 12). On a hit, the cord is cut. Additionally, if a creature targets the Assimilated Monk with an attack and lands a critical hit, they can choose to cut the cord instead of attacking the monk. When the cord is cut, the monk dies.

Evasion. When the Assimilated Monk is subjected to a Dexterity saving throw, they instead take no damage on a success, and half damage on a failure.

Mobile. When the Assimilated Monk makes a melee weapon attack against a creature, that creature cannot make an opportunity of attack against the Assimilated Monk for the rest of its turn, regardless of whether it hits.

Multiattack. The Assimilated Monk makes two attacks with its Unarmed Strike.

Unarmed Strike. Melee Weapon Attack: +9 to hit, reach 5 ft., 1 target. Hit: 10 (1d10 + 5) bludgeoning damage. On a hit, the Assimilated Monk may attempt to subject a target to one of the following effects:

• The target must succeed on a DC 16 Strength saving throw or drop one item of the monk's choice.
• The target must succeed on a DC 16 Dexterity saving throw or be knocked prone.
• The target must succeed on a DC 16 Constitution saving throw or be stunned until the end of the monk's next turn.

Dash. The Assimilated Monk can take the dash action as a bonus action.