Dagger of the Barbed Devil 2014
Weapon, rare
You gain a +1 bonus to attack and damage rolls made with this magic weapon. You can use an action to cause sharp, pointed barbs to sprout from this blade. The barbs remain for 1 minute. When you hit a creature while the barbs are active, the creature must succeed on a DC 15 Dexterity saving throw or a barb breaks off into its flesh and the dagger loses its barbs. At the start of each of its turns, a creature with a barb in its flesh must make a DC 15 Constitution saving throw. On a failure, it has disadvantage on attack rolls and ability checks until the start of its next turn as it is wracked with pain. The barb remains until a creature uses its action to remove the barb, dealing 1d4 piercing damage to the barbed creature. Once you cause barbs to sprout from the dagger, you can't do so again until the next dawn.
Properties
Finesse
When making an attack with a finesse weapon, you use your choice of your Strength or Dexterity modifier for the attack and damage rolls. You must use the same modifier for both rolls.
Light
A light weapon is small and easy to handle, making it ideal for use when fighting with two weapons.
Thrown (range 20/60)
If a weapon has the thrown property, you can throw the weapon to make a ranged attack. If the weapon is a melee weapon, you use the same ability modifier for that attack roll and damage roll that you would use for a melee attack with the weapon. For example, if you throw a handaxe, you use your Strength, but if you throw a dagger, you can use either your Strength or your Dexterity, since the dagger has the finesse property.
Source: Vault of Magic (Kobold Press) · License: OPEN GAME LICENSE Version 1.0a details