Ambusher. The kenku has an advantage on attack rolls against any creature it has surprised.

 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.

Sunlight Sensitivity. While in sunlight, the zombie has disadvantage on attack rolls, as well as on Strength checks.

Shortsword. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) piercing damage.

Bite: Melee Weapon Attack: +3 to hit, reach 5 ft., one creature. Hit: (1d6 + STR) piercing damage.

Infect: Bonus action: If the target is hit by the bite attack, the target must succeed on a 12 Constitution save. On a failed save, the target takes 2d6 necrotic damage and suffers from the poisoned condition. The target can reroll the Constitution save at the end of each turn to end the condition.