New Cantrip: Magic Toxin

Transmutation Cantrip
Casting Time: 1 action
Range: 5 feet
Components: V, S, M (a weapon)
Duration: Instantaneous
As part of this spell, you make a melee weapon attack. If you hit, you deal weapon damage + 1d6 poison damage and cause the target to suffer Disadvantage on the next attack roll it makes before the end of its next turn.
5th: 2d6
11th: 3d6
1th: 4d6