Corpse Centipede

Undead Fortitude. If damage reduces the Corpse Centipede to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant damage. On a success, the Corpse Centipede drops to 1 hit point instead.

Many Heads: The Corpse Centipede has multiple heads and many eyes, as such it can easily detect enemies hiding from it, the Corpse Centipede cannot be surprised other than if it is unconscious.

Vulnerable to Holy Flames: The Corpse Centipede is weak against fire and Holy energies due to the processes used to create it, each time it takes radiant or fire damage it takes extra 5 damage of the respective type.

Multiattack; The Corpse Centipede can make six Slam attacks.

Slam: Melee weapon attack: +8 to hit, 5ft range for 1d6+4 bludgeoinng damage.

Twist and Twirl: (recharge 6): all creatures within 10ft of the Corpse Centipede must succeed a Dexterity saving throw DC 15, taking 2d6+4 bludgeoning damage on a failure, half as much on a success.