Cat Got Your Tongue

You attempt to prevent a creature within range from speaking. The creature must make a Wisdom saving throw or become unable to communicate verbally until the spell ends. When the creature speaks, fur balls erupt from their mouth, giving the creature disadvantage on all Charisma checks.  

Additionally, whenever the creature attempts to cast a spell with a verbal component, they must make a Constitution saving throw. If the saving throw fails, the spell is lost but not expended, and the creature takes 1d6 psychic damage. On a success, the spell is cast as usual.