Petty Bastard

You are sick of your foes assuming they're better than you, stronger than you, cooler than you and have turned to petty insults as a result. You gain the following benefits

Your Charisma score increases by 1, up to a maximum of 20.
You learn Vicious Mockery (if you do not already know it). Charisma is your spellcasting modifier for this spell.
When any creature within 30 feet of you fails an attack roll, you may cast Vicious Mockery on them as a reaction. You may use this part of Petty a number of times equal to your proficiency bonus, restarting each long rest