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.
Unusual Nature. The zombie doesn't require air, food, drink, or sleep.
Javelin. Melee Weapon Attack: +1 to hit, reach 5 ft., one target. Hit:2 (1d6 - 1) piercing damage.
The necromancer Vellynne Harpell has Icewind kobold guides in her employ, including a pair that died and were turned into zombies using animate dead spells. The cold climate helps to preserve their dead flesh.