Infection. The zombie carries an infectious disease it can spread to living creatures. The disease attack the creature's system, reducing it's Hit Points maximum by 3 (1d6) for every hour that passes after.

While reduced to below half it's maximum hit points by the disease, the creature has the Poisoned condition. If it's Hit Points maximum is reduced to 0 by the disease, it dies, and rises 1 hour later as an Infectious Zombie hostile to all living creatures.

Creatures immune to the poisoned condition are immune to this disease, and a lesser restoration spell or similar magic cures it. A cured creature 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.

Enraged. The zombie has advantage on all melee weapon attack rolls relying on strenght, but attack rolls against it are made at advantage. The zombie also has advantage on strenght checks and saving throws.

Siege Monster. The zombie deals double damage to objects and structures.

Multiattack. The zombie makes two melee attacks.

Slam. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 20 (4d6 + 6) bludgeoning damage.

Bite. Melee Weapon Attack: +9 to hit, reach 5 ft., one creature. Hit: 15 (2d8 + 6) piercing damage. If the target is a creature, it is subjected to the following effect. Constitution Saving Throw : DC 15. Failure : The target becomes infected with the disease described in the Infection trait.

Rock. Ranged Weapon Attack: +9 to hit, range 60/180 ft., one target. Hit: 33 (5d10 + 6) bludgeoning damage, and the target is subjected to the following effect. Strenght Saving Throw : DC 17. Failure : The target has the Prone condition.

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