Bite of opportunity

Biter: Spend one attack to make a bite attack, if successful target makes a will save DC = 8+proficiency+ability modifier used in attack, if save fails then anyone else with this feat can trigger the opportunist trait of this feat

Opportunist: use reaction to make an attack at advantage against the target, if this attack has a saving throw tire to it, that save is made at disadvantage

Any combination of these may used a number times equal to proficiency bonus and recharged on a long rest