As an action, you can create a vial of liquid that contains three easy-to-miss bubbles shaped like Zs. A creature can drink the contents as an action. The creature must make a Will saving throw.
On a failed save, the creature falls unconscious. The creature is unconscious until the effect ends, the sleeper takes damage, or someone uses an action to shake or slap the sleeper awake.
This is a charm effect. Undead and creatures immune to being charmed aren’t affected by this effect.