Bag of Nails, Sr.

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

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

Feline Agility. When Bag of Nails moves on its turn in combat, he can double his speed until the end of the turn. Once he uses this trait, Bag of Nails can't use it again until he moves 0 feet on one of his turns.

Sneak Attack. Once per turn, the assassin deals an extra 35 (10d6) 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.

Multiattack. Bag of Nails makes three attacks.

Claw. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 6 (1d4 + 6) slashing damage.

Shortsword. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 9 (1d6 + 6) piercing damage, and the target must make a DC 19 Constitution saving throw, taking 31 (9d6) poison damage on a failed save, or half as much damage on a successful one.

Longbow. Ranged Weapon Attack: +11 to hit, range 150/600 ft., one target. Hit: 10 (1d8 + 6) piercing damage, and the target must make a DC 19 Constitution saving throw, taking 31 (9d6) poison damage on a failed save, or half as much damage on a successful one.

Shadow Step (Recharge 4–6).
Teleports up to 60 ft. to a spot he can see in dim light or darkness and becomes invisible until the start of his next turn or until he attacks.

Cunning Action. Dash, Disengage, or Hide.

Parry. Adds +6 to AC against one melee attack that would hit him.

Death Instinct (1/Day).
When reduced to 0 HP, Bag of Nails instead drops to 1 HP and immediately makes one weapon attack with advantage.

Legendary Action Uses: 3 (4 in Lair). Immediately after another creature’s turn, Bag of Nails Sr can expend a use to take one of the following actions. Bag of Nails Sr regains all expended uses at the start of each of its turns.

1. Move. Move up to half his speed without provoking opportunity attacks.

2. Quick Shot (2 actions). Make one ranged weapon attack.

3. Vanishing Leap (3 actions). Teleport up to 30 ft. and make a Stealth check to hide.