Infectious Zombie

Infection. The zombie carries a magical infectious disease it can spread to living creatures. Creatures immune to the Poisoned condition are immune to this disease.

While infected, a creature has the Poisoned condition, and it's Hit Points maximum is reduced by 3 (1d6) every hour that passes after being infected. If it's Hit Points maximum is reduced to 0 by the disease, it dies, rising 1 hour later as an Infectious Undead hostile to all living creatures. if it dies from another source, it rises 1 hour later all the same.

A Lesser Restoration spell, Remove Curse spell, or similar magic cures an infected creature, which becomes Immune to the disease for 24 hours and has it's Hit Points maximum restored after it finishes a long rest.

Undead Fortitude. If damage reduces the zombie to 0 Hit Points, it makes a Constitution saving throw (DC 5 plus the damage taken) unless the damage is Radiant or from a Critical Hit. On a successful save, the zombie drops to 1 Hit Point instead.

Slam. Melee Weapon Attack : +4 to hit (with Advantage if the target doesn't have all its Hit Points), reach 5 ft., one creature. Hit : 5 (1d6 + 2) Bludgeoning damage. If the target is a Medium or smaller creature, it has the Grappled condition (escape DC 12) from one of two hand.

Bite. Melee Weapon Attack : +4 to hit (with Advantage if the target doesn't have all its Hit Points), reach 5 ft., one creature. Hit : 5 (1d6 + 2) Piercing damage and 3 (1d6) Poison damage. If the target is a creature, it is subjected to the following effect : Constitution Saving Throw, DC 12, Failure : The target becomes infected. Success : The target has Advantage on saving throws against that disease for 24 hours.

Feeding Frenzy. The zombie can move up to its speed toward a hostile living creature that it can see.