Corpsefire

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

Spectral Hit. Corpsefire adds a random magical effect to each of his Slam attacks.

   1. Fire. Add 3 (1d6) fire damage to every creature within 5 feet of Corpsefire.
   2. Cold. Add 3 (1d6) cold damage. If the target is a creature, it must succeed on a DC 15 Constitution saving throw, or its movement speed is halved, and it can't take reactions or bonus actions for 1 minute.
   3. Lightning. Two bolts of lightning leap from the target to two other target within 15 feet. A target can be a creature or an object and can be targeted by only one of the of the bolts. Each target must make a DC 15 Dexterity saving throw, taking 7 (2d6) lightning damage on a failed save or half as much on a successful one.
   4. Necrotic. Add 7 (2d6) necrotic damage and Corpsefire regains hit points equal to the necrotic damage dealt. There is no limit to the hit points that can be gained this way.
   5. Poison. Add 3 (1d6) poison damage, and the target must succeed on a DC 15 Constitution saving throw or be poisoned for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
   6. Psychic. Add 3 (1d6) psychic damage, and the target must succeed on a DC 15 Wisdom saving throw or be blinded for 1 minute.

Slam. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) bludgeoning damage.