Monsatan's Genocidal Rod
If your garden is overrun by pests, Monsatan has the answer for you! The infernal magic channeled into this rod will clear out even the toughest of garden (or dungeon) nuisances! And as an added upside, any food grown in the area for the next twenty years will cause birth defects! It's a win-win!
Only a warlock can attune to this rod. While attuned, you gain a +2 bonus to all attack rolls, damage rolls, and the saving throw DC to resist your spells. In addition, you can spend an action to restore a warlock spell slot of any level once per day.