Murk Blowgun

A hefty blowgun used by the inhabitants of the Murk: a series of deadly swamps whose waters are polluted with an uncanny poison. When you hit a creature with a ranged attack using this magic blowgun, that creature takes an extra 1d4 poison damage. When you roll a 20 on a ranged attack roll made with the blowgun, the target must also succeed on a DC 13 Constitution saving throw or be poisoned until the end of its next turn. It is incapacitated while poisoned in this way. In addition, this blowgun can be wielded as a magic club.

Ammunition: You can use a weapon that has the ammunition property to make a ranged attack only if you have ammunition to fire from the weapon. Each time you attack with the weapon, you expend one piece of ammunition. The ammunition of a firearm is destroyed upon use. Drawing the ammunition from a quiver, case, or other container is part of the attack (you need a free hand to load a one-handed weapon). At the end of the battle, you can recover half your expended ammunition by taking a minute to search the battlefield. If you use a weapon that has the ammunition property to make a melee attack, you treat the weapon as an improvised weapon (see "Improvised Weapons").

Range: A weapon that can be used to make a ranged attack has a range shown in parentheses after the ammunition or thrown property. The range lists two numbers. The first is the weapon's normal range in feet, and the second indicates the weapon's maximum range. When attacking a target beyond normal range, you have disadvantage on the attack roll. You can't attack a target beyond the weapon's long range.

Loading: Because of the time required to load this weapon, you can fire only one piece of ammunition from it when you use an action, bonus action, or reaction to fire it, regardless of the number of attacks you can normally make.

Proficiency: martial, blowgun Source: The Griffon's Saddlebag: Book Two p. 128 (Third Party)