Allergen

You weave a bundle of magic that will trigger an allergic reaction in a creature, then either infuse it into a creature you can see within 30 feet of you or into an object you touch.

Creature. The target makes a Constitution saving throw. On a failed save, it is poisoned, and while it is poisoned it cannot breathe or speak. At the end of each of its turns, it must make a Constitution saving throw. On a failed save, it immediately loses a minute of time that it has to hold its breath, up to the point where it begins suffocating. On a successful save, it is no longer poisoned. The poisoned condition ends after 1 minute.

Object. You touch a non-magical object that isn’t being worn or carried no larger than 1 foot in any dimension, making it a magical allergen. You can choose whether it will only cause a reaction in a specific creature you are familiar with, or any creature. You also choose whether the reaction triggers when the object is touched or eaten. When a creature that can be affected by the allergen touches or eats the allergen (whichever triggers it), the creature effect above triggers against the creature, and it makes its initial save with disadvantage. A creature can tell that the object will trigger a harmful reaction in itself with a Wisdom (Perception) check against your spell save DC. The allergen loses its magic after it is triggered or after 24 hours.