Assassin

Medium humanoid (any race), any non-good alignment

Armor Class 15 (studded leather)
Hit Points 78 (12d8 + 24)
Speed 30 ft.

Saving Throws Dex +6, Int +4
Skills Acrobatics +6, Deception +3, Perception +3, Stealth +9
Damage Resistances poison
Senses passive Perception 13
Languages Thieves' cant plus any two languages
Challenge 8 (3,900 XP)

Assassinate. During its first turn, the assassin has advantage on attack rolls against any creature that hasn't taken a turn. Any hit the assassin scores against a surprised creature is a critical hit.
Evasion. If the assassin is subjected to an effect that allows it to make a Dexterity saving throw to take only half damage, the assassin instead takes no damage if it succeeds on the saving throw, and only half damage if it fails.
Sneak Attack. Once per turn, the assassin deals an extra 14 (4d6) 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 assassin that isn't incapacitated and the assassin doesn't have disadvantage on the attack roll.

Actions

Multiattack. The assassin makes two shortsword attacks.
Shortsword. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) piercing damage, and the target must make a DC 15 Constitution saving throw, taking 24 (7d6) poison damage on a failed save, or half as much damage on a successful one.
Light Crossbow. Ranged Weapon Attack: +6 to hit, range 80/320 ft., one target. Hit: 7 (1d8 + 3) piercing damage, and the target must make a DC 15 Constitution saving throw, taking 24 (7d6) poison damage on a failed save, or half as much damage on a successful one.

Description

Trained in the use of poison, assassins are remorseless killers who work for nobles, guildmasters, sovereigns, and anyone else who can afford them.