Cursed miasma. An attacker who reduces the zombie fighter's HP to 0, must make a constitution saving throw (DC 12) or become cursed. A cursed humanoid creature will rise as a zombie when its own HP is reduced to 0 instead of making death saving throws.

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.

Overwhelming hoard. The zombie has advantage on an attack roll against a creature if at least one other allied zombie is within 5 feet of the creature and the ally isn’t incapacitated. 

Spear. Melee or Ranged Weapon Attack: +7 to hit, reach 5 ft. and range 20/60 ft., one target. Hit: 11 (2d6 + 4) piercing damage, or 13 (2d8 + 4) piercing damage if used with two hands to make a melee attack.

Shield Bash. Melee Weapon Attack: +7 to hit, reach 5 ft., one creature. Hit: 9 (2d4 + 4) bludgeoning damage. If the target is a Medium or smaller creature, it must succeed on a DC 15 Strength saving throw or be knocked prone.