Dagger of Venom

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.