Chronological Zombie

Chronological Magic. The zombie is immune to all types of damage except damage dealt from critical hits and radiant damage. At the start of each of its turns the zombie takes 3 radiant damage.

Limb Loss. Whenever the zombie would take 15 or more slashing damage from one attack, roll a d20 to determine what happens to it:

• 1-10: Nothing happens.
• 11-14: One leg is severed from the zombie, it becomes prone and it's movement is reduced to 5.
• 15-18: One arm is severed from the zombie and it looses a slam attack.
• 19-20: The zombie is decapitated and is considered blind, deaf and loses its bite attack.

Multiattack. The zombie makes two melee attacks.

Slam. Melee Weapon Attack: +3 to hit, reach 5 ft., 1 target. Hit: 4 (1d6 + 1) bludgeoning damage. 

Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., 1 target. Hit: 4 (1d6 + 1) piercing damage.