Orner's Venomous Crossbow

This magic crossbow carries a small system of curious tubes and vessels. You gain a +1 bonus to attack and damage rolls made with this magic weapon. The crossbow has 4 charges and regains 1d3 + 1 expended charges daily at dawn. You can expend 1 of the weapon's charges when you make an attack with it to coat the fired bolt with a unique, self-generating venom. If the attack hits, the target takes an extra 1d6 poison damage and must make a DC 13 Constitution saving throw. On a failed save, the target is poisoned until the end of its next turn. If you expend the crossbow's last charge, roll a d20. On a 1, the vessels attached to the crossbow shatter and spray poison in a 20-foot-radius sphere centered on your location. Creatures within the sphere take 1d12 poison damage and must succeed on a DC 15 Constitution saving throw or be poisoned for 1 minute. When this happens, the crossbow ceases to be magical and loses all of its additional properties

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.

Light: A light weapon is small and easy to handle, making it ideal for use when fighting with two weapons.

Proficiency: martial, hand crossbow Source: The Griffon's Saddlebag: Book Two p. 132 (Third Party)