Blowgun

Ammo: needle [5.5e]

Vex (Mastery): If you hit a creature with this weapon and deal damage to the creature, you have Advantage on your next attack roll against that creature before the end of your next turn.

Ammunition: You can use a weapon that has the Ammunition property to make a ranged attack only if you have ammunition to fire from it. The type of ammunition required is specified with the weapon's range. Each attack expends one piece of Ammunition: Drawing the ammunition is part of the attack (you need a free hand to load a one-handed weapon). After a fight, you can spend 1 minute to recover half the ammunition (round down) you used in the fight; the rest is lost.

Loading: You can fire only one piece of ammunition from a Loading weapon when you use an action, a Bonus Action, or a Reaction to fire it, regardless of the number of attacks you can normally make.

Proficiency: martial, blowgun Source: Player's Handbook (2024) p. 215