Cunning Action. On each of its turns, the spy can use a bonus action to take the Dash, Disengage, or Hide action.

Sneak Attack (1/Turn). The spy deals an extra 7 (2d6) damage when it hits a target with a weapon attack and has advantage on the attack roll, or when the target is within 5 feet of an ally of the spy that isn't incapacitated and the spy doesn't have disadvantage on the attack roll.

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.

Multiattack. The spy makes two melee attacks.

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

Hand Crossbow. Ranged Weapon Attack: +3 to hit, range 30/120 ft., one target. Hit: 5 (1d6 + 1) piercing damage.