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.

Zapish defence. These Zapish Zombies have a permanent mage armor spell cast on them. 

Zapish Self-destruct. When a Zapish Zombie dies all creatures within 10ft must make a dc 14 constitution saving throw taking 18 (4d8) lightning damage on a failure and half as much on a success.

Zapish Slam. Melee Weapon Attack: 4 to hit, reach 5 ft., one target. Hit: 4 (1d6 + 1) bludgeoning damage plus 8 (2d6+2) lightning damage.

Zapish breath (recharge 5-6). The Zapish Zombie releases a bolt of lightning from it's mouth in a 15-foot  line that is 5 feet wide. Each creature in that line must make a DC 11 dexterity saving throw, taking 18 (4d8) lightning damage on a failed save, or half as much damage on a successful one.