Weight: 0.05 lb.
Estimated Value (Sane Cost Guide): 2,500 gp
DMG Value: 501 gp - 5,000 gp
You gain a +1 bonus to attack and damage rolls made with this magic weapon. You can use an action to cause thick, black poison to coat the blade. The poison remains for 1 minute or until an attack using this weapon hits a creature. That creature must succeed on a DC 15 Constitution saving throw or take 2d10 poison damage and become poisoned for 1 minute. The dagger can’t be used this way again until the next dawn.
Source: DMG p161