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.

Infection. When A Zombie Make's A Bite Attack On A Creature It Must Make A DC 10 Dexterity Saving Throw Or A DC 10 Constitution Saving Throw To Redirect The Attack To Somewhere On Their Armor (Still Taking The Damage) Or Trying To Resist It's Effects. The Creature Loses 3 Max Hitpoints Everyday and You Become A Zombie After Your Hitpoint Maximum Reaches 0 Or You Become Unconsious, And You Rise The Next Day.

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

Bite. Melee Weapon Attack: +3 to hit, reach 5 ft., one target. Hit: 4 (1d4 + 3) piercing damage.