Aramis [Doppelganger Assassin]

Shapechanger. Aramis can use its action to polymorph into a Small or Medium humanoid it has seen, or back into its true form. Its statistics, other than its size, are the same in each form. Any equipment it is wearing or carrying isn't transformed. It reverts to its true form if it dies.

Ambusher. Aramis has advantage on attack rolls against any creature it has surprised.

Surprise Attack. If Aramis surprises a creature and hits it with an attack during the first round of combat, the target takes an extra 10 (3d6) damage from the attack.

Assassinate. During its first turn, Aramis has advantage on attack rolls against any creature that hasn't taken a turn. Any hit Aramis scores against a surprised creature is a critical hit.

Evasion. If Aramis is subjected to an effect that allows it to make a Dexterity saving throw to take only half damage, Aramis instead takes no damage if it succeeds on the saving throw, and only half damage if it fails.

Sneak Attack. Once per turn, Aramis deals an extra 14 (5d6) 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 Aramis that isn't incapacitated and Aramis doesn't have disadvantage on the attack roll.

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

Multiattack. Aramis makes two melee attacks.

Shortsword of Warning +1. Melee Weapon Attack: +9 to hit, reach 5 ft., one target. Hit: 8 (1d6 + 5) 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. (While the weapon is on Aramis, they have advantage on initiative rolls. In addition, they and any of their companions within 30 feet of them can’t be surprised, except when incapacitated by something other than nonmagical sleep. The weapon magically awakens them and their companions within range if any are sleeping naturally when combat begins.)

Light Crossbow+1. Ranged Weapon Attack: +9 to hit, range 80/320 ft., one target. Hit: 9 (1d8 + 5) 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.

Slam. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 7 (1d6 + 4) bludgeoning damage.

Read Thoughts. Aramis magically reads the surface thoughts of one creature within 60 feet of it. The effect can penetrate barriers, but 3 feet of wood or dirt, 2 feet of stone, 2 inches of metal, or a thin sheet of lead blocks it. While the target is in range, Aramis can continue reading its thoughts, as long as Aramis’s concentration isn't broken (as if concentrating on a spell). While reading the target's mind, Aramis has advantage on Wisdom (Insight) and Charisma (Deception, Intimidation, and Persuasion) checks against the target.

Uncanny Dodge. The thief halves the damage that it takes from an attack that hits it. The thief must be able to see the attacker.