16 (studded leather)
58 (9d8 + 18)
25 ft.
Acrobatics +7, Perception +4, Stealth +7
poison
darkvision 120 ft.
Dwarvish, Undercommon
5
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.
The duergar has advantage on saving throws against poison, spells, and illusions, as well as to resist being charmed or paralyzed.
Once per turn, the assassin deals an extra 10 (3d6) 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.
While in sunlight, the assassin has disadvantage on attack rolls, as well as on Wisdom (Perception) checks that rely on sight.
For 1 minute, the duergar magically reduces in size, along with anything it is wearing or carrying. While reduced, the duergar is Tiny, and reduces its weapon damage to 1. It gains a +5 bonus to all Dexterity (Stealth) checks and a +5 bonus to its AC. It can also Hide as a bonus action on each of its turns.
Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) piercing damage plus 3 (1d6) poison damage. Can cast darkness once a day.
Ranged Weapon Attack: +8 to hit, range 80/320 ft., one target. Hit: 7 (1d8 + 3) piercing damage plus 3 (1d6) poison damage, or 1 piercing damage and 3 (1d6) poison damage when reduced. Can cast darkness once a day.
The duergar magically turns invisible until it attacks, casts a spell, or uses its Enlarge, or until its concentration is broken, up to 1 hour (as if concentrating on a spell). Any equipment the duergar wears or carries is invisible with it.