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 Attack Roll: +6, reach 5 ft. Hit: 13 (2d8 + 4) Bludgeoning damage.