Wyrm's Breath Amulet

This amulet is shaped like a serpentine dragon coiling around a bubbling cauldron. While wearing this amulet, you can use your action to exhale a toxic mist in a 15-foot cone. Each creature in that area must make a Constitution saving throw (DC 13) or take 3d6 poison damage and become poisoned until the end of their next turn. On a successful save, they take half damage and are not poisoned. You can use this feature once per short or long rest. Additionally, you have advantage on saving throws against being poisoned while wearing this amulet.